Crystal Gulch

Past Producer in Alaska, United States with commodities Silver, Gold, Bismuth, Tin, Uranium

Geologic information

Identification information

Deposit ID 10001652
MRDS ID A012426
Record type Site
Current site name Crystal Gulch
Related records 10282025

Geographic coordinates

Geographic coordinates: -154.78295, 63.23337 (WGS84)
Relative position The Crystal Gulch placer deposit is in a steep, southerly-facing, first order gulch located at 900 feet (274 m) in Section 13, T. 26 S., R. 21 E., of the Kateel River Meridian. Location is accurate to within 100 feet (30 m).
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Silver Primary
Gold Primary
Bismuth Secondary
Tin Secondary
Uranium Secondary

Comments on the commodity information

  • Gangue = Very abundant magnetite

Materials information

Materials Type of material
Bismuth Ore
Brookite Ore
Cassiterite Ore
Gold Ore

Mineral occurrence model information

Model code 121
USGS model code 39c
BC deposit profile C01. C02
Deposit model name Shoreline placer Ti

Nearby scientific data

(1) -154.78295, 63.23337

Comments on the geologic information

  • Geologic Description = The rich Crystal Gulch placer deposit occurs in a steep first order tributary of Ruby Creek. Stream gradient averages about 500 feet per mile (650 m/km). Most of the values occurred at the intersection of the gulch with Ruby Creek. The Crystal Gulch deposit was exhausted by 1924. The uranium mineral brookite was identified by Mertie (1936). Concentrates averaged 5 percent cassiterite during the life of the operation. (Ted Almasy, personal communication, 1998). Age of mineralization is unknown, but judged to be Quaternary, based on comparative geomorphological features in southwest Alaska (Bundtzen and Miller, 1997).

Economic information

Economic information about the deposit and operations

Development status Past Producer
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name McGrath

Comments on the production information

  • Production Notes = Production estimates are lumped with other properties on Ruby Creek, which produced a total of 1,511 ounces (47 kg) of gold prior to 1942.

Comments on the workings information

  • Workings / Exploration = The placer deposit was mined exclusively by surface-hydraulic methods (Brown, 1926; Mertie, 1936).

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS A012426
USGS Alaska Resource Data File ARDF MD070

Bibliographic references

  • Deposit

    Brown, J.S., 1926, The Nixon Fork country: U.S. Geological Survey Bulletin 783. p. 97-144.

  • Deposit

    Mertie, J.B., Jr., 1936, Mineral deposits of the Ruby-Kuskokwim region, Alaska: U.S. Geological Survey Bulletin 864-C, 115-245.

  • Deposit

    Cobb, E.H., 1974, Synopsis of mineral resources and geology of Alaska: U.S. Geological Survey Bulletin 1307, 53 pages.

  • Deposit

    Bundtzen, T.K., and Miller, M.L., 1997, Precious metals associated with Late Cretaceous-early Tertiary igneous rocks of southwestern Alaska, in Goldfarb, R.J., and Miller, L.D., eds., Economic Geology Monograph #9, Mineral Deposits of Alaska, p. 242-286.

  • Deposit

    Cobb, E.H., 1978, Summary of references to mineral occurrences in the Beaver, Bettles, and Medfra quadrangles: U.S. Geological Survey Open File Report 78-94, 54 pages.

Comments on the references

  • Primary Reference = Mertie, 1936

General comments

Subject category Comment text
Deposit Model Name = Placer Au-PGE (Cox and Singer, 1986; model no. 39c)
Deposit Other Comments = See also Ruby-Strand (MD069), Birch Gulch (MD073), Holmes Gulch (MD0 72), Encio Gulch (MD063) and Upper Ruby Creek (MD068).

Reporter information

Type Date Name Affiliation Comment
Reporter 07-JUN-98 Bundtzen, T.K. Pacific Rim Geological Consulting