Rainbow Ridge Mine (Monarch Opal Mine; Roop Mine), Virgin Valley, Humboldt County, Nevada, USAi

Regional Level Types
Rainbow Ridge Mine (Monarch Opal Mine; Roop Mine)	Mine (Active)
Virgin Valley	Valley
Humboldt County	County
Nevada	State
USA	Country

The Rainbow Ridge Opal mine is a group of six patented placer mining claims known as the Black Opal #1, Black Opal #2, Black Opal #3, Rincon Belle, Royal Opal, and Pandora claims. It was known by other names prior to relocation & placer patent (Monarch Opal Mine, 1913). The mining claims are located in Sections 22-23, T45N R26E, MDBM.

The deposit was originally discovered sometime around 1908 where opal chips were found eroding on the east side of a small hill. The first official location at Rainbow Ridge was made by Mr. MGhee, a local rancher, under the name "Opal claim" in 1911 after which the Rincon Belle lode (1912) and Monarch Opal lodes (1913) were located by Deb Roop, Ed McGhee, George Hill and McGuffey. The Roop/McGhee claims were the original lode locations that later became the Rainbow Ridge Opal Mine (USGS, 1984 p.__); Eckert, 1997 p.__). This in-place deposit was known to be a valuable producer of both gem and specimen opals since 1912-1913 as detailed by the U.S. Geological Survey reports at the time as well as affidavits of assessment work showing extensive workings and improvements. Sometime about 1916, author Flora Loughead (phonetically pronounced "Lockheed"), mother of the famed Lockheed (engineering/Aircraft) boys, came to Virgin Valley to write a story, and became enamored with the opals and area. She purchased the McGhee/Roop claims and then relocated the claims as placers (among other claims in the valley) and in 1917-1918 formed the Rainbow Ridge Mining Company with the Hammond-Fiske family, of which Ward's Natural Science Establishment (New York) was a shareholder. The Monarch lodes were relocated as the Black Opal #1-2 placers and the Rincon Belle lode was relocated as the Rincon Belle placer.
As the near surface opal-bearing exposure and workings became deeper, a tunnel was driven from the old main Monarch pit on the south east side of the Ridge to follow the defined subsurface zone of opal-bearing material, and later in 1917-1918 a tunnel was driven from the west side to meet the eastern underground drive.

The period of 1917-1918 produced some very large and spectacular opals from the main drive of the underground workings. The first was known as the "Grubstake" which weighed ___ carats. In November 1917 the Black Opal claims of the Rainbow Ridge Group (previously Monarch claims) produced the famous fist-size precious Roebling Black Opal weighing 2,585 carats (17 ounces) from the underground tunnel, which in 1920 was held to be worth US$250,000.- and called the most expensive opal ever found (at the time) which was subsequently acquired by mineral collector Washington Roebling, and donated in 1926 to the U.S. National Museum where it still resides in the permanent collection of the Smithsonian Institution. The Roebling Opal was discovered by a miner named Lew Thompson working in the main underground drive for Flora Lockheed and the Rainbow Ridge Mining Company. Many large and significant opals were found in the underground workings between 1917-1921. One account of mining during this time period recalls that 5-gallon buckets full of valuable opals were left in the tunnel overnight, to be stolen by highgraders. In 1925 a mineral survey was performed on the Rainbow Ridge Group of claims which at this time consisted of six placer claims. Subsequently, the Rainbow Ridge Mining Company applied for patent to the Rainbow Ridge placer claims, (*add survey notes here*). Patent for the six placer claims was issued in 1929-1930. The Mineral Patent to the Rainbow Ridge Mining Claims contained a reservation excluding any lodes previously known to exist by virtue of federal statute. Under the U.S. Mining laws, placer claims could be patented for half the cost ($2.50 per acre) of a lode claim ($5.00 per acre), but known lodes would remain excluded per 30 U.S.C. 37.
Lockheed still made trips to the mine even in her elderly years up to the late 1930's/early 1940's, with Mark Foster managing the claims for her. At one point after 1937, Mark Foster located a claim on Rainbow Ridge. Flora Lockheed passed away in 1943 and the Rainbow Ridge Mine was subsequently acquired by Harry Foulkes, who sold it to the Hodson family in 1949. In 1952, the mine produced the now famous 6.3 pound "Fathers Day" (Hodson) Opal discovered by Keith Hodson in the main underground drive. The Hodson's opened the mine to fee digging. In 1985 or 1986 Keith Hodson began opencutting the back side of the ridge (the location of the original Monarch lode pit and tunnels of the Black Opal placers). The Hodson's formed Rainbow Ridge Opal Mines Inc. (1987), which currently (2019) still operates the mine, managed by Glen Hodson. In the early 1990's Keith Hodson located the Rincon Belle Extension lode on the west side of the patented Rincon Belle Placer, as an extension of that deposit.

As of 1991, there was an estimated 850 to 1,000 feet of underground tunnel in the main workings. A large opencut now exists where the original east side tunnel was located and has obliterated some original workings and tunnels. The mine has been operated as a fee dig site during the summer months for decades. Many fine opals have been recovered by both fee diggers and the mine owners alike. The southern end of the Ridge has been known to produce the best opal. Projections of the strike and dip of the in-place deposit suggest substantially more opal bearing ground.




Commodity: Several very large and many small opals

Deposit: 6 claims were patented in 1929. Over 20 acres of mineable deposit. The 2.95 kg hodson black fire opal was discovered in 1952. The first discovery of precious opal in virgin valley is reported to have taken place in 1905 or 1906 at this site. The original claims were owned by d. Roop, e. Mc gee, and g.t. Hill. Opal chips were found on the e. Side of a small hill in 1908 and a 300-ft long tunnel was dug. In 1917, the roebling opal, weighing 2,665 carats (553 g) was found here. At the time of its discovery, it was valued between $50,000 and $250,000. In 1929, 6 claims were patented: royal opal, rincon belle, black opal nos. 1, 2, 3, and pandora. Little work was done at the mine from 1920 until 1949 when keith hodson purchased the claims and began several crosscuts and a drift. In 1952 he discovered the hodson black fire opal weighing 2.95 kg, then valued at $50,000. Little work has been done recently at the rainbow ridge mine, due to mr. Hodson's work on the virgin opal claims. Development consist of 2 large cuts, 8 smaller pits and 750 ft. Of underground workings. Listed in 1980 As an active surface mine employing 2 persons. ; info.src : 1 pub lit; 2 unpub rept discovery year: 1905 or 1906

Development: The 2665-carat roebling opal was found here in 1917. Listed in 1980 As an active surface mine employing 2 persons. Still active at least through 1985.

Geology: The opal-bearing horizon averages 4 ft. Thick and is mainly bentonite with pods of ash, rhyolite pebbles, petrified wood, and opal. The amount of petrified wood increases downward with the opal-bearing horizon. Precious opal occurs As "conk" and in void fillings left where wood has rotted away. "Conk" is formed when opal fills the voids between growth rings in partially petrified wood. The opalescence of the black fire opals is equal to the best in the world; but the quality for cut gems is poor.

Ore(s): Precious Opal Occurs As "Conk" And In Void Fillings Left Where Wood Has Rotted Away.

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Link to USGS MRDS:	10045025

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