Alum Rock Park: Albandite & Hausmannite Rockhounding in Santa Clara County, California
- Minerals reported
- 3
- Elevation
- 560 ft
- Best months
- Year-round
Alum Rock Park is a mapped rockhounding spot in Santa Clara County, California. Reported finds include albandite, hausmannite, tephroite. Below: coordinates, access notes, nearby spots, and trip-planning links.
Plan your visit
Generally open to casual rockhounding
- County
- Santa Clara County
- State
- California
- Nearest road
- Penitencia Creek Trail
- Postcode
- 95127
- Coordinates
- 37.39579, -121.80192
Coordinates are approximate. Confirm the exact ground in the RockHoundR app, where land overlays show which agency manages the area.
Land & collecting status
Generally open to casual rockhounding
Most public-tagged spots sit on BLM, U.S. Forest Service, or other federal land where reasonable hand collecting of common rocks and minerals is allowed. Confirm posted rules and active mining claims before you dig.
Public-land rules vary by agency, season, and field office. The RockHoundR app pulls live BLM, USFS, NPS, and tribal overlays so you can see exactly which agency manages the ground at this spot.
Best time to visit Alum Rock Park
Comfortable months (45 to 90°F highs)
Conditions here are workable year-round, with typical highs from 57°F in winter to 80°F in summer.
Climate normals: NOAA 1991-2020 monthlies, SAN JOSE station (7 mi away), adjusted for elevation.
Geology at Alum Rock Park
This spot sits on ground mapped as Alluvium, undivided that formed within roughly the last 3 million years. Loose deposits like these are float-collecting ground: erosion keeps moving durable rocks and minerals into gravel bars, cutbanks, and washes.
- Mapped unit
- Alluvium, undivided
- Age
- 3 Ma to present (Quaternary)
- Elevation
- 560 ft
Geologic mapping via Macrostrat and the underlying state geological survey maps (CC BY 4.0). Bedrock at the surface can vary within a mapped unit.
Today's weather
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The app shows live weather, recent rain, and a daily rockhounding score for Alum Rock Park.
Get the appSources & verification
Spot details combine the public RockHoundR location dataset, normalized mineral labels, agency land-status checks in the app, and community submissions. Coordinates are approximate until verified in the field.
State guidance last verified:
- BLM California, Recreational mineral collecting
- California Geological Survey
- CDFW, Suction Dredge Mining Permit Program
- Community submissions reviewed against published agency rules
Found at Alum Rock Park
Each name opens all spots that produce that material; the encyclopedia link opens the full ID and field guide.
Albandite
Hausmannite
Tephroite
Nearby rockhounding spots
Other rockhounding spots within driving distance of Alum Rock Park.
- Guadeloupe CreekSanta Clara County, California · 14 mi awayDendritic Agate
- New Almaden Area MinesSanta Clara County, California · 15 mi awayChert, Cinnabar, Apophyllite
- Coyote CreekSanta Clara County, California · 21 mi awaySiderite
- Morgan Hill CreeksSanta Clara County, California · 25 mi awayPoppy Jasper
- Coyote PointSan Mateo County, California · 31 mi awayChert, Jasper
- Crystal Springs ReservoirSan Mateo County, California · 34 mi awayChromite
- Poplar BeachSan Mateo County, California · 36 mi awayAgate
- Unnamed Location (Mariposite)Mariposa County, California · 90 mi awayMariposite
Alum Rock Park FAQ
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