USGS Mineral Resources Data System
Type: Historical mine record
Supports:
- mine identity
- development status
- commodities
- underground eligibility evidence
Nevada · Mineral County
Big Twenty Mine
Unconfirmed Silver Underground
Key facts
- State
- Nevada
- County
- Mineral
- Development status
- Past Producer
- Mine type
- Underground
- Primary commodity
- Silver
- Verification
- Unconfirmed
Also known as
- NBMG # 3784
Mine Location
Approximate AreaDocumented underground workings
Mindat locality description
Alteration: Sericitization Of Country Rock Deposit: Three sub parallel veins, a continuation of the vein at mountain view mine, ranging from a few inches to 4 feet wide. The croppings of the veins consist of iron-stained quartz, underground they are r…
Historical mapped workings
USGS historical topographic mapping. Features may no longer exist.
- 10 shaft symbols
- 18 adit symbols
View individual source records (2)
Every underlying record used to build the summary above, for research/verification use.
- USGS MRDS working type: Underground
- MRDS work_type documents underground workings: Underground · work_type
Verification
Unconfirmed
Source records support underground workings, but UndergroundMines has not yet independently verified this mine.
Why it's listed
USGS source data documents underground workings for this record.
History & operations
Historical record
- Development status: Past Producer
Commodities & minerals
Reported minerals
- Quartz
- Gold
- Pyrite
- commodity:Gold
- commodity:Silver
- Diorite
- Native Gold
- Native Sulphur
View all 10 reported minerals
- Quartz
- Gold
- Pyrite
- commodity:Gold
- commodity:Silver
- Diorite
- Native Gold
- Native Sulphur
- Pyrite
- Quartz
Access & recent conditions
- Land
- unknown
Community reports
No community field reports yet.
I Visited This MineSources & evidence
USGS Historical Topographic Mine Features
Type: Historical mapped physical features
Dataset: DOI 10.5066/P9TAALR6
Supports:
- mapped shaft symbols (10)
- mapped adit symbols (18)
Historical mapped features may no longer exist.
Mindat
Type: Mineralogical locality database
Record: Mindat Locality: 431544
Supports:
- locality identity
- reported minerals (7)
A Mindat locality match does not by itself establish underground workings.
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