Goldmanite is a rare vanadium-bearing garnet belonging to the ugrandite series. It is typically found in metasomatized sandstone deposits and contact metamorphic zones where vanadium-rich fluids have reacted with host rock.
Is this goldmanite?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch goldmanite with a known reference. Goldmanite sits at Mohs 7, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: white.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: dark green, brownish green.
- 5Look at form & habitCrystal system: cubic. Typical habit: crystalline.
Often confused with
Goldmanite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside goldmanite
Minerals reported to co-occur with goldmanite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ca₃V₂Si₃O₁₂
- Mohs hardness
- 7
- Density
- 3.74-3.77 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Cubic
- Crystal habit
- Crystalline
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In a small metamorphosed U{V deposit in sandstone, embedded in vanadium-rich clays and calcite (Sandy mine, New Mexico, USA); in calcareous metapelites and tungsten-bearing skarns (Coat-an-Noz, France); detrital
Where rockhounds find goldmanite
Classic worldwide localities
- Sandy mine, near Laguna, Valencia Co., New Mexico, USA
- Coat-an-Noz, Côtes-du-Nord, France
- Tetetice, Klatovy, Czech Republic
- Ishimskaya Luka, northern Kazakhstan
- Slyudyanka complex, Sayan Mountains, near Lake Baikal, Siberia, Russia
- Yamoto mine, Kagoshima Prefecture, Japan
Field-hunting tip
Where it forms: In a small metamorphosed U{V deposit in sandstone, embedded in vanadium-rich clays and calcite (Sandy mine, New Mexico, USA); in calcareous metapelites and tungsten-bearing skarns (Coat-an-Noz, France); detrital. If you start seeing quartz, calcite, diopside in float, you are in the right ground. Typical habit: crystalline. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify goldmanite?+
Where is goldmanite found?+
Is goldmanite safe to handle?+
What rocks look like goldmanite?+
What minerals are found with goldmanite?+
What kind of rock does goldmanite form in?+
What is goldmanite used for?+
Find goldmanite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
