Bonanza Opal Mine (Virgin Mine; Virgin Opal Mine; Bon 1-5 lodes; Defiance Mine; Mathewson-Dow Opal Mine), Virgin Valley, Humboldt County, Nevada, USAi

Regional Level Types
Bonanza Opal Mine (Virgin Mine; Virgin Opal Mine; Bon 1-5 lodes; Defiance Mine; Mathewson-Dow Opal Mine)	Workings
Virgin Valley	Valley
Humboldt County	County
Nevada	State
USA	Country

The Bonanza Opal workings are a precious opal deposit and mine group, located primarily in the SW¼ section 6, T45N, R26E, MDM, at an elevation around 5,200 feet. The patented portion of the mine is 103 acres. The early history of the Virgin Opal-Bonanza deposit is vague, but was one of the earliest claims in Virgin Valley.

The original discovery of opals in the area is reported to have occurred about 1905-1906 at what is now the nearby Opal Queen Mine just S-SE of the Bonanza Mine. The Bonanza deposit was discovered, staked and became the second major location in Virgin Valley. Ivan Dow, George Mathewson, Alfred Thompson and others were the original owners (1908). At this time it was known as "Bonanza" or the "Mathewson/Dow" Mine. The deposit was first officially reported by J.C. Merriam in 1907.

The early workings at the Bonanza were shallow surface cuts along the dip and exposure of opal-bearing horizons or zones. Some years later, after 1916, Flora Loughead (pronounced "Lockheed") acquired the Bonanza group claims, which was one of the ten major groups she owned during her mining efforts in Virgin Valley.

In January, 1943 Flora Lockheed died and the Bonanza deposit was relocated on April 3, 1943, as the Virgin Opal Placer by Mark M. Foster, Frank L. Garaventa, and others, being 2,640 feet by 2,640 feet, or 160 acres. Mark Foster located a 40 acre addition measuring 2,640 feet by 660 feet on July 1, 1953, known as the Virgin Opal #2 Placer, on the southerly side of the existing Virgin Opal, bringing the amount of ground claimed to 200 acres. The work consisted of a cut to begin tunnel near the north side center line of the new claim.

On December 11, 1954, Mark Foster sold the Virgin Opal group placer claims (Virgin Opal & Virgin Opal #2) to the Hodson family. The Virgin Opal claims were downplayed in their importance by their new owners to discourage highgrading due to the remoteness of the location and the valuable nature of the gems in the exposed deposits, and in literature was purported to "be only a localized enrichment" (Eyles, 1964, p.122), which was not the actual case.

In 1973, while working on the Virgin Opal claim, Keith Hodson accidentally discovered the 7.25 pound "Bonanza" Opal, which was broken into 5 large pieces and numerous smaller chunks by the bulldozer blade. During 1974-1975, the United States Geological Survey examined the Virgin Opal-Bonanza deposit (among other mines in the area) as part of their study of the mineral potential of Virgin Valley and the Sheldon Range (U.S.G.S., 1984, p.1,131-134). On June 15, 1979, Keith Hodson located the Bon #1-5 Lode mining claims over his existing Virgin Opal Group placers for the in-place source deposit and filed a patent application. A mineral survey was conducted on the Bon #1-5 lode claims between June 25-28, 1979. On September 7, 1982, Keith Hodson received a mineral patent to the Bon #1-5 lode claims, patent # 27-82-0024, covering 103.305 acres. The mine was worked for many years by owner Keith Hodson, and in the early 1980's produced a 3,853 carat limb replacement precious opal discovered by Hodson's wife, Agnes, known as the "Crowning Glory" which was valued at $50,000.00 (USA) as a wet specimen. On July 15, 1988, Keith Hodson (dba Rainbow Ridge Opal Mines Inc) sold the patented Bon #1-5 lode mining claims ("Bonanza Opal Mine") to Richard Leger and Lloyd Olds.

Richard Leger and Lloyd Olds formed a limited partnership selling 100 (one hundred) 1% shares in the mine, agreeing that the total of 100 shares would never be increased. Each share gave the shareholder/owner 1% ownership in the mine, corporation, vote, and digging rights to the Bonanza Mine. Initially the shares sold for $6,000.00 each, and averaged $9,000.00 or so in later years. On September 15, 1989, Richard Leger and Lloyd Olds filed the Virgin Opal #1 and #1A placer claims, claiming ground on either side of and buffering the patented Bonanza Opal mine. On October 22, 1991, the Bonanza shareholder partnership formed Bonanza Opal Mines, Inc., a Nevada corporation, consisting of 100 shares total consistent with the original shareholder plan. On July 9, 1992, Lloyd Olds and Richard Leger quitclaimeed their interests in the Virgin Opal #1 and #1A placers to the Bonanza corporation, as well as the patented mine. The Virgin Opal placer claims on either side of the patented Bonanza Opal mine were apparently so valuable that Lloyd Olds stipulated in the deed that the claims were to remain with Bonanza Opal Mines Inc forever or be returned to him upon dissolution of the corporation. The corporation subsequently filed buffer lode claims on both sides of the patented mine.

For some time afterwards, the Bonanza corporation and shareholders were involved in lawsuits over management, ownership and share disputes, among other issues. However, after initiating a shareholder plan for the patented mine, considerable amounts of precious opal was recovered, of which 1/2 went to the corporation and 1/2 to the discovering shareholder; exceptional specimens remained property of the corporation. After legalities were settled, the tailings portion of the mine was open for public fee digging.

The Virgin Opal-Bonanza deposit is underlain by in-place, nearly horizontal to 45 degree dipping ash, tuff, and tuffaceous sandstone beds. The opal bearing horizon can generally be traced 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 Bonanza mine is quite developed and active, with many large trenches, open cuts, pits and workings. The original float (placer) deposits are exhausted; the lode deposit is being actively mined. The mine has produced large precious opals, the most noteworthy weighing 7.25 pounds ("The Bonanza Opal"); 8 pounds ("Irene's Delight"); and other smaller pieces too numerous to mention.

Bonanza Opal Mines Inc., sales for 1995 totaled $47,566 (11/30/1995) and the patented mine yielded a total of 79 gallons of opal from the 1995 season (the corporation's 50% share was 49 gallons of opal, or approximately ten 5-gallon buckets, which was considered to be a "bad" season). Heylmun (1987, p.44) notes that "In places, precious opal has been involved with slumping and landsliding; undoubtedbly, some valuable opal deposits lie buried beneath the landslides." The Virgin Opal-Bonanza deposit was noted as being one of several mines in Virgin Valley having opal reserves worth millions of dollars (USGS, 1984, p.7).

The patented mine, along with the other adjoining claims, transferred by Lloyd Olds and Richard Leger to the Bonanza Corporation, were estimated to be worth not less than $5,000,000.00 (five million dollars USA) in 1987 and 1994 (Defendants, 1996). The Bonanza deposit has also been noted as being one of the two most important mines in the area (Zeitner, 1986 p.44).

Structure: Bedding

Deposit: Probably first located by i. Dow, g. Mathewson, a. Thompson and others in 1908. It was relocated in 1943 by mr. Garaventa As the virgin opal claim. It was purchased in 1955 by the current owner, keith hodson. It is developed by several sizeable cuts, one adit, and a storage building. Listed in 1980 As an open pit mine employing 2 persons. ; info.src : 1 pub lit 1800 ft x 100 ft mineable area

Development: Listed in 1980 As an active open-pit mine employing 2 persons.

Geology: The opal-bearing horizon averages more than 12. 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.

Ore(s): Sedimentary Bedding

Other Databases

Link to USGS MRDS:	10045032
Link to USGS MRDS:	10036999

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References