Rockhounding in Merrimack County, NH: 36 USGS Mineral Sites (2026)

Check access before you go. Most sites listed here are old mines, quarries or prospects, and many are on private land or active mining claims. Get the landowner's permission, check the rules of the agency that manages any public land, and never enter mine workings. Locations are approximate.

Sketch map

Past ProducerProducerProspectOccurrenceStatus unknown

30 paw pins; nearby sites are grouped into one pin. Hover or tap a pin for the site name. 1 site(s) with USGS coordinates outside the outline are not pinned. County outline: US Census Bureau cartographic boundary file (2023). Locations approximate.

Woof’s favorite find

Ney Prospect

We picked it because its USGS record mentions 2 gem or collectible minerals (Gold, Silver) and 3 of our card minerals overall. No other named site here scores as high on both counts. USGS lists it as past producer for Copper. Minerals mentioned: Gold, Copper, Silver. Approx. location 43.419, -71.803. USGS record.

Ask first: a USGS record doesn’t mean you can visit. Find out who owns the land and get permission before collecting.

Field cards: what kind of sites?

Prospect

Explored or test-dug, with no recorded production.

Past Producer

Produced ore or material at some point in the past.

Occurrence

The mineral was noted here, without development.

Producer

Was producing when the record was made.

Unknown

Status not recorded.

Status terms come from USGS MRDS records.

Mineral cards

Mica
Mohs 2–3. Peels into thin, flexible, shiny sheets. Mindat
8 sites
Garnet
Mohs 6.5–7.5. Usually deep red, round many-faced crystals. Mindat
7 sites
Feldspar
Mohs 6–6.5. Blocky crystals with flat cleavage faces. Mindat
6 sites
Silver
Mohs 2.5–3. Native silver tarnishes black. Mindat
3 sites
Copper
Mohs 2.5–3. Native copper is soft and turns green as it weathers. Mindat
2 sites
Gold
Mohs 2.5–3. Soft, heavy and bright yellow; it doesn’t tarnish. Mindat
1 site

Counts are sites whose USGS record mentions the mineral or commodity. Hardness from Mindat.

Minerals recorded here

Granite 1Uraninite 1

Commodities

Silica 9Garnet 6Feldspar 5Mica 5Diatomite 3Granite 2Lead 2Copper 2Talc-Soapstone 2Zinc 1

Sites

Site	Commodity	Minerals recorded	Status	Approx. location
John Swenson Granite Co	Granite	Granite	Past Producer	43.237, -71.572
Otterville I 89 Roadcut Uraninite Occurrence	Uranium	Uraninite	Occurrence	43.414, -72.030
Buswell's Mine	Lead	—	Past Producer	43.308, -71.461
Silverdale Mine	Lead, Zinc	—	Past Producer	43.279, -71.341
Unnamed, Sunapee Mtns.	Bismuth	—	Occurrence	43.283, -72.083
Ney Prospect	Copper	—	Past Producer	43.419, -71.803
Jake Patten Mica Prospect	Feldspar	—	Prospect	43.598, -71.850
West Severance Hill	Garnet	—	Prospect	43.524, -71.903
Hall Mountain Quartz	Silica	—	Prospect	43.088, -71.372
Mica Queen Mine	Feldspar	—	Past Producer	43.471, -71.971
Concord Mica Co/ Penacook, Nh	Mica	—	Unknown	43.281, -71.597
Silverdale Mine	—	—	Prospect	43.279, -71.341
Bickford Pegmatite	Silica, Beryllium, Garnet, Mica, Feldspar	—	Prospect	43.418, -71.956
Wilmot Mica Deposit	Mica	—	Prospect	43.461, -71.971
Campbell Hill Quartz Deposit	Silica	—	Prospect	43.057, -71.431
West Hooksett Quartz	Silica	—	Prospect	43.074, -71.511
Unnamed Mine	Talc-Soapstone	—	Past Producer	43.323, -71.583
Pinnacle Quartz	Silica	—	Prospect	43.097, -71.470
Pleasant Ponds Diatomite	Diatomite	—	Prospect	43.243, -71.755
Hogdon Quarry	Talc-Soapstone	—	Past Producer	43.252, -71.751
Chalk Pond Diatomite	Diatomite	—	Prospect	43.349, -72.011
Brown Brook Quartz	Silica	—	Prospect	43.114, -71.449
Wausau Abrasive Co. Mine	Garnet	—	Past Producer	43.537, -71.897
East Severance Hill Garnet Mine	Garnet	—	Past Producer	43.526, -71.895
Garnet Prospect	Garnet	—	Prospect	43.502, -71.921
Concord Foundry Sand Prospect	Silica	—	Prospect	43.214, -71.500
Canterbury Foundry Sand Prospect 9	Silica	—	Prospect	43.332, -71.615
Dunbarton Quartz Prospect	Silica	—	Prospect	43.070, -71.523
Concord Gray Quarry	Granite	—	Producer	43.237, -71.572
Boston Lead Mine	Graphite	—	Past Producer	43.376, -71.833
Assoc Minerals Consol/Bow Nh.	Zirconium	—	Producer	43.133, -71.549
Danbury Mica Mine	Mica	—	Past Producer	43.593, -71.853
Pickwick Mica Mine	Feldspar	—	Prospect	43.577, -71.877
North Wilmot Garnet Mine	Garnet	—	Past Producer	43.506, -71.931
Pleasant Swamp Diatomite	Diatomite	—	Prospect	43.544, -71.855
W.E. Briggs Property	Mica, Feldspar	—	Prospect	43.496, -71.891

Nearby counties

Sullivan County · Belknap County · Hillsborough County · Grafton County · Cheshire County

New Hampshire mineral guides

Back to all New Hampshire counties.

How we built this page: we counted named sites in the USGS Mineral Resources Data System (MRDS) for this area, left out sand, gravel, crushed stone, clay pits and unnamed sites, grouped them by Census county, and linked every site to its USGS record. We did not visit these sites, and MRDS does not tell you who owns the land or whether collecting is allowed.

Source: USGS Mineral Resources Data System (MRDS). USGS ceased systematic updates to MRDS around 2011, so status and details may be out of date. Each site links to its USGS record.

Updated October 2026

Rockhounding in Merrimack County, New Hampshire

Sketch map

Ney Prospect

Field cards: what kind of sites?

Mineral cards

Mica

Garnet

Feldspar

Silver

Copper

Gold