Stonetree Opal Mine (WRT Stonetree claim; BLM-NMC No. 865655), WRT Stonetree group ("Dominion Opal Mine"), Virgin Valley, Humboldt County, Nevada, USAi

Regional Level Types
Stonetree Opal Mine (WRT Stonetree claim; BLM-NMC No. 865655)	Mine
WRT Stonetree group ("Dominion Opal Mine")	Group of Claims
Virgin Valley	Valley
Humboldt County	County
Nevada	State
USA	Country

The Stonetree deposit was one of the earliest mining claim locations in the Virgin Valley Mining District. Although known to exist much earlier in time, it was first "officially" reported by D.B. Sterrett in 1913 as being owned by "several parties". At one time the mine was owned by renowned Flora H. Loughhead ("Lockheed") Gutierrez, and was referred to in 1916-1918 as the "Giant Tree" Opal Claim, and was sold by Gutierrez to the Rainbow Ridge Mining Company in 1918. Between 1918 to 1940, the surface float and alluvial (placer) deposits of opal were exhausted and the claim subsequently became idle and abandoned. It was relocated as a placer deposit in 1966. In 2004 it was located as a lode (in-place) deposit when it became a part of the ten-claim WRT Stonetree claim group by the Wentzell Revocable Trust. Annual Assessment work and development by agents of The Wentzell Revocable Trust from 2007 to 2019 uncovered large amounts of precious black, crystal, jelly and other opal types, including a large harlequin black opal. The claim obtained its name from the large 30+ foot petrified tree on the property. Mining efforts are undertaken in such a way to protect this landmark fossil for future generations of the public to enjoy. The Petrified Tree is property of the United States and cannot be mined, damaged or claimed. Held by Alvin Wentzell from 2011 until 2022.

The Stonetree deposit is similar to all of the other precious-opal bearing deposits in Virgin Valley. The mining claims are underlain by in-place, horizontal ash, tuff, and tuffaceous sandstone beds. The opal-bearing horizon can be traced and followed and averages more than 4 feet (1.2 m) thick and consists primarily of light-colored bentonite containing varying amounts of petrified wood, rhyolite pebbles, ash, and opal. Precious opals are usually found in the upper half of the horizon. The opal-bearing layer is continuous and in-place. The precious opals which are mined from this deposit are as bright as, if not brighter than, opals from the other area mines. The largest precious opal found on this group of claims was approximately four (4) pounds. Petrified wood is not mined on any of the claims but the precious opal is found in association with petrified wood.

Dominion Opal Mines was in charge of mining and assessment work operations through its agents 2011-2018. Officially known as the WRT Stonetree Lode Mining Claim, BLM-NMC#865655. The Wentzell family sold the claim to Thomas Schaefer in late November 2022, reserving the right to dig for 3 years.

Other Regions, Features and Areas containing this locality

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