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, 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.