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.

Hardness

6.5-7

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

mineralrareGarnet Group family

Goldmanite

Hardness: 6.5-7
Luster: Vitreous
Streak: White
Transparency: Translucent

Is this goldmanite?

5-step field check

Run through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.

1
Test the hardness
Try to scratch goldmanite with a known reference. Goldmanite sits at Mohs 6.5-7 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Goldmanite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Goldmanite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: dark green, brownish green, black.
5
Look at form & habit
Crystal system: cubic. Typical habit: dodecahedral crystals, massive, granular.

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: 6.5-7
Density: 3.7-3.8 g/cm³
Colors: Dark Green Brownish Green Black
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Cubic
Crystal habit: Dodecahedral Crystals, Massive, Granular
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Metasomatized Sandstone, Contact Metamorphic Rocks
Typical price: $50-300 per specimen

Where rockhounds find goldmanite

Classic worldwide localities

Laguna, New Mexico, USA
Kyushu, Japan
Northern Ural Mountains, Russia
Otjosondu, Namibia

Field-hunting tip

Look in metasomatized sandstone, contact metamorphic rocks country — that is the host setting where goldmanite typically forms. If you start seeing montroseite, paramontroseite, quartz in float, you are in the right ground. Field specimens usually show a dodecahedral crystals, massive, granular habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify goldmanite?+

Mohs hardness is 6.5-7. It typically shows a vitreous luster. The streak is white. Common colors include dark green, brownish green, black.

Where is goldmanite found?+

Notable localities include Laguna, New Mexico, USA; Kyushu, Japan; Northern Ural Mountains, Russia; Otjosondu, Namibia.

How much is goldmanite worth?+

Typical asking prices fall in the range of $50-300 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like goldmanite?+

Goldmanite is most often confused with Uvarovite, Grossularite Garnet, Andradite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with goldmanite?+

Goldmanite commonly co-occurs with Montroseite, Paramontroseite, Quartz, Calcite, Barite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does goldmanite form in?+

Goldmanite typically forms in metasomatized sandstone, contact metamorphic rocks. Working float back to the host body is the standard way to chase a fresh occurrence.

What is goldmanite used for?+

Goldmanite is used in collector.

Find goldmanite on the map

RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.