New Arrivals

Intricate Wire Gold Specimens From Nevada District On Sale

From time to time the museum store acquires some interesting gold specimens, and the crystalline gold now on sale from Washoe County, Nevada is truly amazing. You’ll usually see buttery-yellow gold as blebs and tiny specks in a bright white quartz matrix, such as from California’s famed Sixteen-to-One Mine. The most commonly viewed gold on sale is alluvial in origin, thus flattened and rounded. Our specimens from the famed Olinghouse District remind you more of the amazing saw-like crystalline gold coming out of Liberty, Washington (shown at the end of this post) or from Breckenridge, Colorado. Thanks to the intricate wires in the Olinghouse specimens, they make a great addition to any gold collection

This one troy ounce nugget from Warren, Idaho shows typical rounding from water transport; on display in the Main Gallery. Not for sale!
Typical gold blebs in white quartz, from California’s Mother Lode region; on display in the Main Gallery. Not for sale!
Wire gold in a small case is a great addition to any gold collection.

According to the Nevada Bureau of Mines open file report 99-2, the Olinghouse district was first prospected in 1860. Miners located deposits in Fort Defiance Canyon in 1864, and the Green Mountain Mines were located in 1874 (Hill, 1911). Prior to 1900, placer deposits situated in several ravines tributary to Olinghouse Cayon were extensively worked by Wadsworth residents (Overton, 1947). Elias Olinghouse originally came to the area to raise sheep, but after seeing the gold prospecting frenzy around him, his interest in mining started to grow. He eventually bought some claims and later got help from his nephew, Henry J. Olinghouse, in 1903.

In the period from 1897 to 1907, independent miners extracted gold from the shallow underground workings and from placer material on the flanks of Green Hill. A townsite and several mills sprung up, and soon a railway climbed up Olinghouse Canyon to connect the mines to the Truckee Valley below. The region reached its peak of activity from 1905-1907, producing $410,000 in gold and silver values between 1898 and 1903. The old Olinghouse town site is directly to the west of the present Green Hill Mine.

The Olinghouse District is located northeast of Ren0-Sparks in Nevada. (map via Google Maps)

In 1907 inadequate ore reserves contributed to the decline of large scale mining, and the soon only small operators and lease holders managed the properties. The railroad dismantled their tracks in 1909, and sold the steel to the Nevada Copper Belt Railroad, then under construction near Yerington (Myrick, 1962).

The old heart of the Olinghouse District is at 39.6571879,-119.43265. You can see evidence of extensive work to the northeast in this hot, dry area. Beware of existing claims and private property if you visit the district. (map via Google Maps)

Between 1939 and 1954 the Natomas Company explored the alluvial fans at the mouth of Olinghouse and Frank Free canyons. Two attempts were made in the 1960’s to work the eluvial placer deposits on Green Hill, but both operations were unsuccessful. Only intermittent mining activity occurred at Olinghouse until 1986, when Western Goldfields Co. secured land in the eastern part of the district and conducted limited drilling. Phelps Dodge began work in 1991. Alta Gold acquired Phelps Dodge’s interest in 1994.

Tiny quartz crystals in matrix, with wire gold forming in thin threads. (Image source: Mindat.org; credit: copyright Peter Haas)

Mindat describes beautiful specimens coming from the 813 pit at Alta Gold Mine near Olinghouse. The specimens exhibit delicate wire-like structures, probably from lode mineralization in one of the faults crossed by the stream channels. Country rocks in the area include Miocene Columbia River basalt and other Cenozoic basalts and trachytes.

Large specimen from Olinghouse in the collection of Harvard University. (Image source: Mindat.org; photo credit: Copyright 2007 Peter Cristofono)
Intricate wire gold is a challenge to photograph!

If you collect fine gold specimens, come in soon while we still have a good selection to choose from. Be sure to view our gold collection downstairs in the Gold Safe while you’re here!

Crystalline gold from the Ace of Diamonds mine at Liberty, Washington on display in the Main Gallery. Not for sale!

Resources
Forgotten Nevada
Mindat.org
Western Mining History
Castor, S.B. and Ferdock, G.C. (2004), Minerals of Nevada, Nevada Bureau of Mines and Geology, Special Publication 31.
Garside, L.J., and Bonham, H.F., Jr., 1992, Olinghouse Mining District, Washoe County, Nevada; in Reno Area – Northern Walker Lane Mineralization and Structure; GSN Special Pub. No. 15.
Robyn, T. L. 1994, Geology and Ore Controls of the Lower Olinghouse Placer Gold Mine, Nevada; Economic Geology vol. 89, no. 7 p. 1614-1622.
Vanderberg, W. O., Placer Mining in Nevada, NBMG Bull. 27, 1936

Fisher’s Ore-Rock-On Waypoints Database Available on DVD, USB

To help rockhounds and fossil-hunters gearing up for the 2019 field season, the Museum Store recently acquired a shipment of Tim Fisher’s acclaimed Ore-Rock-On collection of GPS coordinates. The database is available on either DVD or USB format, and is a great resource for anyone who wants to explore our region.

Fisher’s web-friendly format uses just about any browser to access rock, mineral, or fossil-hunting site coordinates (also called waypoints) for the Pacific Northwest. You can see what his electronic maps show for an area, and you can download the entire list of waypoints into Google Earth or your mobile device. This helps immensely for planning purposes; you can determine driving distances, nearby locations to check, road numbers, closest campgrounds, parks and towns, etc.

Fisher includes different maps for regional views and individual sites, providing the setting and the exact area. If he has spent considerable time at a locale, he has written up the information, provided pictures of what he found, and even provided digging hints.

Sample Ore-Rock-On map for Cape Blanco.

New to version 6.0 are dozens of specimen photos, and 196 new waypoints, for a total of 2,991 GPS coordinates. The collection includes 295 overview maps, 884 topo maps, 36 site write-ups, and 1,700 pictures. Fisher includes rockhounding, mineral collecting, and fossil hunting locales only; he doesn’t list old gold or silver mines unless they have other interesting materials for collectors.

Over the years, Fisher has studied hundreds of scientific reports, read countless thesis papers from local universities, and attended annual shows to gather his information. In some cases, the locales are indicated with precision; elsewhere, he’s narrowed down the search to a square section. He also works with authors of known rockhounding titles and he updates his information periodically.

Since newer laptops and tablets don’t have a DVD drive, the store also stocked the database in USB formats. If you’re planning some outings this year to explore the Pacific Northwest, you owe it to your expedition to bring pinpoint locations with you, and this product has you covered.

Highly-Sought Purpurite On Sale

The Museum Store now has a large assortment of vivid purpurite available for collectors. This interesting purple mineral makes for an interesting addition to anyone’s collection and is affordably priced. Purpurite would be more popular as a gemstone, if it were not such a rarity.

Purpurite (pronounced “PUR – pu – rite) was named in 1905 by Louis C. Graton and Waldemar T. Schaller from the Latin “purpura” for its purple color. It has a chemical formula of (Mn3+,Fe3+)PO4 which means it is a manganese phosphate with considerable iron present. It forms by leaching lithium from lithiophilite and triphylite, and replacing the vacancy with manganese and iron. There is a complete series from heterosite to purpurite; according to Mindat, “intermediate alteration products are part of a continuous process of alteration: Ferrisicklerite and Sicklerite are intermediate between unoxidized and unleached end-members and the completely leached and appropriately oxidized end-products, but may not be valid species. The Mn:Fe value has not been observed to vary much from the primary lithiophilite to the secondary purpurite.”

Color:  Dark purple to purplish red. Dark brown to brown-black on altered surfaces.

Luster: Dull, Earthy; satiny on fresh fracture surfaces. Dull on altered surfaces.

Hardness:  4 – 4½

Specific Gravity:    3.2 – 3.4

Streak:  Light to medium purple, lighter than the color of the massive mineral.

Tenacity:  Brittle

Cleavage:  Distinct/Good. Cleavage surfaces curved or crinkled at times.

Fracture:  Irregular/Uneven

Transparency:  Opaque

Crystal System: Orthorhombic

Member of:  Triphylite Group

This stone can be found in many locations in the USA, Portugal, France, Namibia, Australia, and Sweden. The type locality for purpurite is the Faires Mine, Kings Mountain, Gaston Co., North Carolina, USA. Much of the material on the market, probably including the stock in the Museum Store, is either from Namibia or from a granite quarry in Portugal that contains large pegmatite veins.

These specimens won’t last long at these prices, so be sure to stop in soon and purchase one!