Olinghouse Article (Originally Published in the Gold Issue, Rocks & Minerals Magazine, Jan-Feb 2004)

By Scott Kleine

 

Introduction-

     The Olinghouse district (Washoe County, Nevada) has produced many hundreds of very fine and unusual wire and nestlike, wiry aggregate gold specimens. Behind the discovery and distribution of these beautiful pieces is a story that bears telling, one that includes memorable experiences at Olinghouse that span a ten-year period.

Location-


     This district is located about 35 miles east of Reno, near the town of Wadsworth. To get there, go through Wadsworth, via I-80 from Reno, toward Pyramid Lake and make a left turn onto the long dirt road cutting back west, leading to the eastern front of the Pah Rah Range. The district is in a large bowl-shaped area, perched halfway up the side of the mountain range, starting at an elevation of about 5,800 feet and going up to about 6,700 feet, The weather can be particularly brutal at Olinghouse--gale-force winds and blowing dust persistently batter anyone on the mountainside. Please note that no permission is given or implied to enter any part of this district. Much of the land is private and posted.

History-


     Early in the 1860s, during the beginning of the earliest Comstock boom, prospectors radiated outward and discovered the Olinghouse district, located about 30 miles north-northeast of Virginia City. Surface prospecting and small-scale underground mining continued for the next four decades, with the rich ore shoots being spotty and hard to find.
     It wasn't until 1901-03 that serious work began on what would be the most intensely worked area in the district, Green Hill. Huge stopes with textbook square-set timbering began permeating the interior of Green Hill because the almost-vertical gold, silver, and copper ore-shoots were mined profitably on a large scale. Some vertical shafts exceeded 400 feet in depth, as the miners dug ever deeper into the rich, golden ores that consisted primarily of crystalline gold encased in calcite. Ultimately, Green Hill became honeycombed with mine workings and covered in dumps.
     Another area worked by the old-time miners was the Babe vein. This area was about one-quarter mile generally southwest of Green Hill. A series of shallow, underground mines explored the ore shoots of this vein. Today, this general area is called the 813 pit.
     In 1906 a railway system was built to Wadsworth to transport the ore output to the new mill and refinery in the valley below. However, during this same time, the district began to suffer a major decline in production, and all of the larger mines began to close. Smaller-scale gold, copper, and tungsten mining persisted through the 1930s. After that, commercial mining all but ceased. A few hardy souls stayed on, endlessly searching for what others had missed. A large placer operation was attempted in the 1980s, at the eastern foot of the district, but little commercial production ever came of this work.
It is almost a certainty that fabulous wire and nest gold specimens were recovered in the old days, as most of the historic 70,000-ounce gold production in the district was free-milling high-grade. Unfortunately, little was saved, and early specimens are not known to be represented in museum collections.
     With the advent of bulk-mineable heap leaching came renewed interest in the hard-rock potential of the district. First on the scene was Phelps Dodge in 1997, but it was unable to find sufficient reserves, and so the property was picked up by Alta Gold Company, which quickly brought it into production. In 1999-2000, while Alta Gold was actively mining in the district, nearly all of the known fine crystallized wire and nest gold specimens were recovered and distributed.
     In April 2000, after about 30,000 ounces of gold production, Alta Gold went bankrupt, and, with only a few hours' notice, Olinghouse operations permanently shut down. This was primarily because of the low price of gold and spotty production. The properties reverted back to the bank that was holding Alta's operational loan. When the bank couldn't sell all the properties, they reverted back to the former owners, who are now engaged in long-term, multiple civil court battles to see who will control the choicest tracts. It is uncertain if another adventurous mining company will try to work Olinghouse once more and if any specimens will be preserved.

Personal Retrospective, 1990-97-

     I first discovered this historic mining district in fall 1990, a few months after moving to Reno to attend the Mackay School of Mines, at the University of Nevada, Reno. While researching Nevada mining districts at the Nevada Bureau of Mines and Geology, I found stone tantalizing information about crystallized gold being found in this district. Being only a forty-five-minute drive from campus, it quickly became an appropriate and often-visited collecting target. At that time, before all of the large-scale mining, the quiet, rustic town of Olinghouse was at the southern edge of the district, with a few hardy landowners still scratching out a meager living from any gold they could find. Locals told of such finds as multi-inch wires and thumbnail-sized golden leaves, but since no one had an actual specimen to show, I was skeptical. These tales did, however, motivate me to climb all over the steep mountains in the district (after getting permission to enter the various properties), looking for my own stories to tell.
      It took a while to learn how to find gold in the district. A lot of time was spent on Green Hill, so-named because intense hydrothermal alteration gave this steep, 500-foot hill a washed-out olive-green color. Countless hours were devoted to climbing its steep dumps in search of bits of overlooked ore. Although the dumps were abundant and voluminous, they infrequently produced a piece with any visible gold. After much observation and collecting, I discovered that, on this hill, amethyst was key. It was critical to look for rare chucks of rock with pale purple veins in them. Sometimes upon breaking amethyst veins and boulders open, my reward would be small (0.5-3-mm), brilliantly crystallized, golden wires and patches packed tightly into open quartz crystal voids. Not once, though, did I find a macroscopic specimen of gold on amethyst crystals.
     Once, high on the side of Green Hill, I found an exposed, unmined, goethite-filled breccia vein some 2 feet wide. A half-dozen 5-gallon buckets of material were collected and arduously lugged home to be panned out, simply for curiosity's sake. The reward in this case was about 0.5 gram of chunky, semicrystalline gold. It was nice to find something, but it wasn't worth the effort to get more of this material because of the remote and inaccessible nature of the vein itself.
     As the years passed, I spent more and more time on the "Babe vein." At an elevation of about 6,000 feet, the "pre-Alta" owner of this property took a large D-series dozer and cut out an impressive 300-foot-long, 20-foot-deep, and 20-foot-wide trench into this veinlike fault zone. He also conducted further underground exploration here and there to the historic workings, with only sporadic, marginal results. His work, however, supplied me with an abundance of newly uncovered quartz-crystal-lined plates. With a bit of hunting and a sharp eye, tiny, 0.25-1-mm, razor-sharp dodecahedra of gold attached to the drusy quartz crystals could be found! A lucky find was a piece that had some purple color to the 1-2-mm quartz crystals that were associated with gold microcrystals. The largest and best of these plates is about 20 x 40 cm and was dug from the Babe vein. The plate was covered in calcite, which I etched, exposing literally hundreds of the wondrous gold microcrystals perched on small white quartz crystals! The gold crystals were so sharp and lustrous that they resembled pyrite.
     My luckiest trip occurred after digging at Olinghouse for more than two years. I had decided to bring home some larger rock plates covered with quartz druse to give my mom as decoration for her rose garden. In all, I brought home six plates from the Babe vein, each of which sparkled quite nicely in the sunshine and showed a tiny gold crystal or two. Several were still a bit muddy, and so I hosed them off in the back yard. One piece had a well-concealed, open, clay-filled void that was lined with quartz crystals. When washed, it revealed a magnificent 1.2 x 0.9 x 0.7-cm nest of heavy wire gold and 0.5-cm grapelike clusters of dodecahedral gold crystals to 1 mm. Eureka! (Sorry, but my mom didn't get that one!) It had taken dozens of trips and several years to find, but now I had my own story to tell, just like the Olinghouse locals from years before. Little did I know what the future still had in store....

Geology-

     The basic geologic framework is concisely described in an unpublished Alta Gold Company report (Cox and Jones 1999) that states: "The district is placed in a complex, heavily faulted volcanic rock setting, with basaltic-to-andesitic flows of the Pyramid Sequence overlaying an older sequence of mostly Oligocene (38 Ma) and Miocene (26 Ma) volcanics, intrusives and related volcanoclastic rock types." Basically, the district is set in a system of heavily faulted and fractured volcanics, with some intrusive igneous rocks. Some of these rock types formed as surface flows, debris slides, and ejected materials, whereas others were dikes, squeezed into the cracks of pre-existing volcanic rocks deep underground. Still others occurred as underground igneous magma pools, creating broad areas of underground heat and mineralized hydrothermal fluid flow.
     Structurally, this district occurs within an active, left-lateral fault system, separating the massive Carson Block from the equally impressive Pyramid Lake Block. Interestingly, of the many faults in the district, the most active structure, the Olinghouse Fault, has shown 1,200 feet of displacement and was the epicenter of a magnitude 6.7 earthquake back in 1869! Today, movement continues to build up tectonic stress in the area, and more quakes are imminent.
     The ore deposits at Olinghouse formed roughly 10-11 million years ago. During this time, many of the district's steeply dipping, northeast-trending faults were intruded by narrow, granodiorite porphyry dikes. Of these, the stockworklike dikes that were nearest to the largest central, deep-seated intrusives hosted the richest areas for epithermal gold mineralization, along with traces of silver and copper. At the same time, another series of generally northwest-trending structures crosscut these northeast-trending ore zones. These fault intersections hosted some of the highest grade ore shoots, where crosscutting, off-set displacement had occurred, allowing the goldbearing fluids to pool and concentrate in the heavily brecciated voids. Ore grades in these shoots range up to many hundreds of ounces to the ton, with most of the gold being crystallized. But, these shoots are typically small and scattered. Only a few possessed large, rich ore zones because postmineralization faulting dissected and off-set the orebodics, fragmenting them into many hard-to-find pieces. It also must be noted that some geologically unrelated scheelite-bearing skarn bodies also occur in isolated places within this district. The area's geology and gold specimen collecting have been described by Bonham (1969) and Lieberman (1989).

Hydrothermal Alteration: During low-temperature hydrothermal gold emplacement, the surrounding volcanic rocks in the district developed a broad propylitic alteration halo about 4 kilometers across. Therefore, much of the volcanic rock has an enhanced green color because of the emplacement of such alteration species as clinozoisite, epidote, and chlorite. Other species, such as quartz, sericitic mica, albite, "adularia," and minor pyrite/chalcopyrite were also deposited, along with rare galena crystals.

Supergene Alteration: Once the deposit was emplaced, the weathering process began. Such species as goethite, azurite, malachite, anglesite, calcite, laumontite, heulandite, and pyrolusite formed from the decomposition of the pyrite, chalcopyrite, galena, and general mafic host rocks. Whether at least some of the gold at Olinghouse also formed under these conditions is currently a topic of hot debate.

Mineralogy-

     The Olinghouse district has a surprising array of mineral species, many associated, at times, with gold-

Anglesite, PbS04, occurs on most of the specimens from the 813 pit that contain galena; the anglesite was initially found as reddish-brown resinous coatings on the gold wires. Later, 1-2-mm pseudohcxagonal, tabular crystals were discovered, though these were rare. XRD verification of this material was made at the University of Nevada, Reno.

Azurite, Cu3(CO3)2(OH)2, is rare on Green Hill; it occurs as blue stains formed by the weathering of chalcopyrite. Associations include minor gold, chalcopyrite, bornite, and pyrite.

Bornite, Cu5FeS4, occurs as iridescent blue rims around chalcopyrite grains in specimens found on and around Green Hill.

Calcite, CaCO3, is a common mineral at Olinghouse. Almost all of the prolific open veins in the district are filled with massive white or brown calcite, yet only rarely do these contain any trace of gold. The calcite acts as a mask, obscuring the gold-bearing veins from the predominate ones that contain nothing. Yet, almost all of the gold-bearing veins found in 1999-2000 were originally filled with calcite, thankfully preserving and protecting the fine wires of gold from blast shock and heavy equipment during the mining process. Crude, etched calcite crystals, to 2 cm, of scalenohedral habit were seen on occasion but were not of collectible quality.

Chalcopyrite, CuFeS2, occurs as brassy-metallic, 1-4-mm, poorly formed grains on or near Green Hill. It is primarily located in deposits near gold-beating structures and is the primary mineral for almost all of the secondary copper-beating species in the district. It can sometimes be confused with gold at this locality.

Clinozoisite, Ca2Al3(SiO4)3(OH), is common on Green Hill, which is aptly named because of its highly propylitic nature--it is loaded with clinozoisite and to a lesser extent epidote. The clinozoisite tends to occur as minute, drusy, yellow-green crystals replacing feldspar phenocrysts and portions of the general rock mass. A few vugs display nice amethyst crystals growing on green druses of clinozoisite at the Babe vein (pre-Alta mining). Other associations include scheelite and the ubiquitous calcite vein filling. The best clinozoisite-gold associations are in the Zeolite vein, 813 pit. Some of these gold-bearing veins show patches and localized surfaces of yellow-green microcrystalline clinozoisite and epidote.

Coloradoite, HgTe, hessite, Ag2Te, and petzite, Ag3AuTe2, occur in rare high-grade specimens containing tellurium-bearing grains to 1 mm, encased in bornite. They have been found in highly brecciated, highly propylitized rocks from the old workings in Green Hill. Identification was determined by both polished-section and SEM/EDAX analyses.

Epidote, Ca2(Fe3+,Al)3(SiO4)3(OH), occurs as microcrystalline druses on fault surfaces and is typically associated with clinozoisite. Epidote can be determined by its color, a darker green than that of clinozoisite. Epidote crystallization is identical to that of the clinozoisite and may occur with the nest-gold specimens from the 813 pit.

Epistilbite, Ca,Al2Si6O12*5H2O, was first discovered in Nevada at Olinghouse. The only piece seen has 2-3-mm blocky crystals associated with scheelite and small gold crystals. Analysis was made by X-ray diffraction (XRD) at the University of Nevada, Reno.

Galena, PbS, was first discovered by an Alta Gold Company geologist as l-mm cubes encased in white calcite and closely associated with crystals of gold. One specimen from Green Hill had gold intergrown with a galena microcube.
     Later, during the excavation of the 813 pit, galena crystals to 1.5 mm were occasionally seen interspersed on the matrixes of a few of the more sparsely covered gold specimens. Curiously, 0.5-1.0-mm somewhat corroded galena crystals perched on the sides of freestanding microwires of gold have been observed.

Garnet, Ca3Al2(SiO4)3, has been observed in a few rare examples as fairly lustrous, yellow-orange crystals to 2 mm in rugs located directly west of the 813 pit. It is not known what type of garnet this is, but grossular would be a good guess.

Goethite, Fe3+O(OH), is a common species at this mine. Notable occurrences include goethite psedomorphing pyrite, with exsolved gold near the surfaces of the replacement. These have only been found on the southern flank of Green Hill.

Gold, * Au. Of the four active pits in the Olinghouse district (the 813, 830, 831, and Green Hill open-pit mines), nearly all of the gold specimens came from localized zones in the 813 and Green Hill pits.

Green Hill: Green Hill was the first place Alta Gold Company chose to mine. This pit is a northeast-trending, 800-foot-long, 200-foot-wide, and 50-200-foot-deep trench cut on the southwest portion of the hill. Wire gold specimens of particularly good size and quality began to be recovered there in early 1999. For the next six months while the pit was being mined, Green Hill produced about 180 specimens of wire gold on crystallized quartz. Of these, about 140 were thumbnail to small miniature in size, displaying one or a few small wires 0.2 1.2 cm in length. Only about 40 showed wires more than 1.2 cm. These aesthetic specimens are highly prized by collectors, especially in Europe, where many of the finer pieces ultimately went.
     These Green Hill finds were made in a series of ore boulders that were exposed during mining; some that contained thick, white, calcite-filled fractures were recognized and preserved. When etched, heart-stopping butter-yellow wires of gold were revealed, precariously attached to attractive druses of sparkling 0.2-1.0-cm quartz crystals, all on an olive-green andesite matrix. One day, a 180-pound boulder was found with a broad, 15-cm-thick, calcite-filled, quartz-crystal-lined void. It was partially etched so that only 3-4 cm of calcite remained. Several wires could be seen protruding upward. Later, my company purchased this boulder from Alta. It was carefully trimmed down to more than two dozen 5-15-cm plates that were then etched and prepared to completion. Some thirty superb gold wires were discovered on matrix, ten more than 3 cm in length and a few to 5 cm!
     A small group of specimens from Green Hill displayed terminated amethyst crystals, to 2 cm in length, in association with fine wires of gold. Less than five quality specimens of this sort were recovered, all with pale to moderate purple tones. The 15-cm specimen pictured (fig. 6) is the finest wire-gold-on-amethyst specimen preserved from Olinghouse, with individual wires from 3 cm to an incredible one of about 7 cm.


The 813 Pit: This is the most prolific nest-gold producer in the district. The main specimen zone was dubbed the "Zeolite vein" because weathering filled fractures in this fault zone with laumontite and heulandite for the first four levels down from the surface. Below this, only calcite filled the vein. Located within this calcite and some of the zeolites were abundant and stunning nests of interlocking microwire gold. From mid-1999 through 2000, this 7-cm-wide and 6-meter-long zone produced approximately 920 nest-gold specimens. In April 2000, at the 6,030-foot bench level, a rich ore shoot was discovered that produced about two-thirds of the total specimens from this zone.
     These golden nests occur in a wide range of colors, habits, and associations. One of the biggest curiosities about the gold from the Zeolite vein is the fact that its color varies so much--from a pale, bleached-out silver-gold, through beautiful butter-yellow hues, to dark bronzelike tones. These variations are not simply from pocket to pocket but can be centimeter to centimeter within the same pocket. Most likely this is due to wildly varying amounts of silver within this gold. This alloy probably ranges down to about 60 percent gold and 40 percent silver. A bulk assay of gold from these nests was made, and they averaged about 70 percent gold and 30 percent silver (Pete Evatt, pers. com., 2000). This variation may be a clue that the high-grade ore shoots in this district are multi-episodic. In other words, the different purities of gold formed in different stages during the development of the pocket, creating these unique, intricately woven nests.
     The general structure and habit of these golden nests are as multitudes of splitting, dendritic, intergrown, curving wires 2-4 mm long and 0.1-1.0 iron thick, with varying amounts of "leafiness." Most of these specimens formed as moderate-to-dense fillings in veins not exceeding 1 cm in thickness. Some of these gold-coated surfaces can exceed 150 square centimeters and are extremely attractive. Other specimens show bushy nests more than 3 cm thick! But these tend to be patchy and localized. Overall, the largest nest-gold specimen is estimated to contain about 3 ounces in gold-alloy weight. It is approximately 15 x 10 x 3 cm and occurred as a thick, loose vein section in calcite (Ed Coogan specimen). The gold is not thickly matted in most nests. A density measurement was made on a series of average gold nests, it is estimated that these have about 1-1.5 grams of alloy per cubic centimeter of nest (Evatt, pers. com., 2000).
     Obvious preferred crystal growth is exhibited by wires within some golden nests. In these, individual wires appear to have formed by repeated spinel twinning that has resulted in extreme wirelike elongation, interestingly, adjacent wires reflect light in such a way that the parallel orientation of these elongated twins is apparent, suggesting some master orientation within the nest as a whole. Similar parallelism of reflections is common in herringbone or dendritic golds from many localities in which the elongation of individual twin aggregates is not so extreme, suggesting that the Olinghouse wires may be parallel branches from some master "trunk" wire buried within the nest. Perhaps unraveling one of these nest like wire aggregates would result in the easy identification of such a master wire from which the others actually diverge.
     Typically, the leafier the gold, the better the color and luster and the more likely spinel twining is present. Leaves range from 0.1-1.0 cm, some even showing rare hexagonal crystallization. Overall, good leaf-gold specimens from the 813 pit constituted only about 5 percent of the collectible specimens.
     Another curious habit of these gold nests is the "garland" variety. These are longer-than-average wires, 0.3-3+ cm, with stubby, smaller wires protruding perpendicularly from their sides. These garlands--which look much like holiday decorations--may be another example of multiple spinel twinning.
     About 95 percent of all the nest-gold specimens prepared by Alta Gold Company were recovered on the olive-green andesite matrix. Some of this matrix shows coatings of clinozoisite/epidote microcrystals underlying sparkling quartz druses. The average-quality specimen from the 813 pit has a flattened, less than 5-cm matrix surface with a 1-cm patch or two of nest gold on it, under 1 cm in thickness. The better pieces show more profile to the matrix and are richer in gold: they may even show better developed leaf forms (> 2 mm). The best specimens are those showing well-developed brecciation of the andesite matrix. These specimens can display aesthetic, multiple vugs containing nest gold and have a higher propensity for large leaf gold (from 0.5 to 1.0 cm). Also popular are the vein, or sandwich, specimens. These are 0.2-2.5-cm-thick gold-nest veins sandwiched laterally between pieces of andesite matrix to 12 cm across. They have the appearance of the quintessential "storybook" sparkling gold vein in rock.
      One issue that has arisen, mostly relative to more silver-rich specimens, is that some of these nests have a tendency to darken over time. It is thought that some of the silver in the alloy can oxidize and darken, becoming coated with acanthite microcrystals, giving the nests a brownish-black look. This might indicate that some of the silver occurs outside of the gold alloy, in its own native form. This oxidation can be directly attributed to environment. Consequently, it is recommended that all Olinghouse gold specimens be kept away from native sulfur and any other minerals that give off H2S gas. Humidity, heat, sunlight, and salt-air conditions may also stimulate this process.

Heulandite, (Na,Ca0.5,K)9(Al9Si27O72)*~24H2O, at Olinghouse was formed by weathering and has only been found within 30 meters of the surface. It has the traditional salmon-pink color and is typically seen as pearly cleavage faces to 2 cm. Some nest-gold specimens from the 813 pit have been found in association with crystalline masses of this species. Heulandite and laumontite from Olinghouse look much the same when first exposed; however, heulandite is stable and will not desiccate like laumontite.

Laumontite, Ca4Al8Si16O48*18H2O, is one of the most common zeolite minerals from Olinghouse. It occurs as a solid crystalline vein fill and is most frequently seen at the Zeolite vein, 813 pit. When first recovered, it typically has a creamy white or pinkish color, a moderate translucency, and pearly cleavage faces. Over time, it has a tendency to dehydrate and turn chalky and white, then destabilize and crumble. Of the few nest-gold specimens from the 813 pit that contain laumontite, the best method of preservation is the use of super glue once this zeolite has turned chalky or begins to become unstable. When the glue is properly applied, the laumontite will immediately absorb it like a sponge, returning the mineral to its original color, luster, and translucency, without any traces of residue left on the surface. I recommend not saturating the laumontite with too much glue, or a sticky mess will result. This species was verified by XRD at the University of Nevada, Reno.

Manganese oxides, ~Mn4+O2, can be found throughout this district; weathering has produced a myriad of interesting, dendritic fans of this material, the largest being about 20 cm, on near-surface fracture faces.

Orthoclase, variety adularia, KAlSi3O8, occurs as small, curving, rhombohedral, creamy white crystals to 4 mm in the areas around the 813 pit. Associations include microcrystals of gold, quartz, and calcite. Tiny (1-mm) adularia rhombs are also present on the matrix of a specimen showing an unusual association of wire gold with scheelite.

Pyrite, FeS2, occurs as small (1-2-mm), typically altered cubic crystals in open vein segments throughout Green Hill.

Quartz, SiO2, at Olinghouse can be very showy. Some of the most impressive specimens are the Green Hill plates of quartz with wire gold. These quartz crystals are typically terminated, translucent, and free standing at various angles; they range in size from 0.2 cm to more than 2 cm. Most have lightly etched faces, giving them a slightly frosted look. Very few truly lustrous quartz crystals have been seen associated with gold from Olinghouse. Other unusual quartz-gold associations are those rare examples of wire gold with amethyst crystals to 2 cm. Amethyst of fine quality has been found here in crystals to 4 cm, hut not with gold.

Scheelite, CaWO4, was first discovered at this district on a single boulder where pseudo-octahedra of white scheclite to 1 mm were found, associated with tiny wires of gold, all on a druse of clinozoisite, on the south side of Green Hill. The crystals fluoresce bright blue, indicating a complete lack of powellite in them.
     Another, more important find was made in a structure parallel to the Zeolite vein, in the 813 pit. A 5-gallon bucketful of random calcite vein chunks was collected from this structure. After going through gallons of hydrochloric acid, two miniatures consisting of stout bushes of bright wire gold to 1 cm, associated with white, equant scheelite crystals to 7 mm, were discovered (species confirmed by XRD at the University of Nevada, Reno). Some of the wire gold was actually included in scheelite! It would seem that these extremely rare specimens were created when gold mineralization was overprinted with later skarn mineralization. Further scarching for more of these specimens ended in frustration.

Personal Retrospective, 1997-2000-

     In 1997 Olinghouse was in for some big changes. Phelps-Dodge started an aggressive sampling program with the intent to open-pit mine in this district. One day I arrived to find thousands of neatly stacked bags, full of assay samples, along with up to six drill rigs. This was very exciting because I knew that if an open-pit mine was developed in this district, tremendous new exposures would be made and wonderful specimens of crystallized gold might begin to appear.
     Later, in early 1998, I learned that Phelps Dodge had stopped work in the district, and my heart sank. However, I quickly found out that the Alta Gold Company had bought the rights to the deposit and was going to begin mining later that year. In November I took a trip up to the mine and, to my great joy, saw 80-ton haul-packs running ore to the new mill site! I excitedly drove to the mine office and introduced myself. I openly offered my experience in the district to the gracious geologists, and soon we all became friends.
     January 1999 saw the first specimen-quality gold being found from this operation. For the next month or so, a few specimens trickled out during the mining of Green Hill. Fortunately, the geologists working at Olinghouse had taken the time to talk with the higher management of Alta Gold, convincing them to preserve as many gold specimens as possible, even though it meant more work for them. Fortunately, these arrangements were made prior to any find of major importance, and the topic was only hypothetical until the first significant finds a few months later During this time, I persistently and successfully worked toward representing Alta Gold as a business consignee for a portion of any future gold specimens produced (which I felt would be inevitable). Along with me, Alta also chose Ed Coogan and Pieter and Debra Heydelaar of Global Treasures to help disperse any gold lots. Soon we all became friends and eagerly awaited news of a big strike.
     Then, in March 1999, the first good gold pocket was discovered at the 813 pit. About 0.5 pound of crystallized gold was recovered from a small ore shoot on the Zeolite vein. I had the dream-come-true privilege to help clean and prepare these hundred-plus beautiful specimens for distribution to collectors. Pieces ranged from thumbnails to small cabinet specimens; all showed wonderful nests of wire gold. One unique specimen consisted of a baseball-sized mass of cream-white, translucent laumontite with about 1 cm of gold wire sticking out each end. An electrical conductivity test was made, and, sure enough, both ends were attached to each other! I was given the piece to trim to better expose the wire. So, I sat in the mine office with a pair of pliers and very carefully hand-trimmed it into a superb specimen. When finished, the wire was 8.4 cm long and up to 2 mm wide! A small, marble-sized mass of laumontite was left for matrix and contrast. Needless to say, I fell in love with this specimen and was ultimately successful in officially acquiring it from Alta for my personal collection. I was blown away, as my biggest self-collected gold wire was a mere 3 mm!
     During this same period, through about June, two parcels of Green Hill matrix wire gold were also dispersed. Three more large lots of 813 pit nest gold were dispersed over the next fourteen months. The first of these was given to us on consignment in September 1999. This lot contained about 250 pieces, split three ways. Most of the pieces were about 2-4 cm and attractive. The next lot, consigned to us in January 2000, also contained about 250 pieces. These specimens were better and larger than those in the previous lot but still predominantly less than 5 cm--only about 25 percent were more than 5 cm. The final lot came to us in August 2000. This lot contained about 320 specimens, with about 80 percent being miniature or larger in size! Five or six large-cabinet specimens were also included. These ranged to 20 cm in size, had excellent gold coverage, and were spectacular! There were also a number of fine leaf specimens in smaller sizes, with leaves from 0.3 to 1.0 cm.
Over a period of less than two years, my company had the privilege to handle about 370 of these fabulous Olinghouse gold specimens. From my commissions for these sales, I decided to take advantage of this lifetime opportunity and acquire a fine group of these pieces for myself, many of which are pictured in this article.

Specimen Preparation-

     The removal of the calcite vein fill was easy. A simple solution of hydrochloric acid worked well. Care was taken, though, to make sure not too much of the calcite was removed or the gold would have become unstable and pieces would begin to fall off. The specimens were completely neutralized for at least twelve hours to prevent iron-oxalate staining, especially when the specimens had bits of goethite with them. After being bathed in an ultrasonic cleaner and rinsed off, they were ready to be enjoyed.

Conclusion-

     The Olinghouse district has produced many unique specimens and may one day become a classic U.S. locality for crystallized gold. For me, it was a great honor to be part of the Olinghouse adventure. I started by spending countless enjoyable days looking for micros and ended up handling and distributing pounds of beautiful crystallized gold! I will always treasure these memories and the representative specimens that I kept for myself.

ACKNOWLEDGMENTS-

     First and foremost, I would like to thank my friend, former Alta Gold Company geologist Pete Evatt. Without his assistance, knowledge, and hard work, all eleven hundred of the gold specimens recovered would have ended up in the crusher, I would also like to acknowledge Brian Jones, John Cox, and former Alta Gold Company president Bob Pratt for their efforts to preserve these specimens. In addition, I thank Dr. Robert Cook and Dr. Peter Modreski for reviewing the article, Jeff Scovil for his fine photography, and William Besse for his cartography.

REFERENCES-

- Bonham, H. F. 1969. Geology and mineral deposits of Washoe and Storey Counties, Nevada. Nevada Bureau of Mines and Geology bulletin 70.
- Cox, J. W., and B. K. Jones. 1999. Olinghouse gold mine. Alta Gold Company, unpublished report B.8.9.
- Lieberman, M. 1989. Gold mineralization at Olinghouse, Nevada. Rocks & Minerals 64:397-403.

SCOTT KLEINE
Great Basin Minerals
scottkleine@greatbasinminerals.com


Unless otherwise noted, all mineral photos by Jeff Scovil of specimens in the author's collection

Scott Kleine, who has a bachelor of science degree in geology, is an avid collector and a full-time mineral dealer.

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