Star Garnet is a variety of almandine garnet containing needle-like rutile inclusions oriented to create a four or six-rayed star effect via asterism. They are typically found as dodecahedral crystals in schist and require careful polishing to reveal the star properly. Emerald Creek in Idaho is world-famous for producing these unique specimens.
Is this star garnet?
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 star garnet with a known reference. Star Garnet sits at Mohs 7-7.5 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Star Garnet leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Star Garnet typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: reddish-brown, dark red, black.
- 5Look at form & habitCrystal system: isometric. Typical habit: dodecahedral crystals with inclusions.
Often confused with
Star Garnet vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside star garnet
Minerals reported to co-occur with star garnet. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Fe₃Al₂(SiO₄)₃
- Mohs hardness
- 7-7.5
- Density
- 3.5-4.3 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Opaque
- Crystal system
- Isometric
- Crystal habit
- Dodecahedral Crystals with Inclusions
- Cleavage
- None
- Rarity
- Uncommon
- Uses
- Collector, Gemstone, Lapidary
- Host rock
- Metamorphic Schist
- Typical price
- $10-100 per rough specimen, higher for cut stones with strong stars.
Where rockhounds find star garnet
1 mapped spotsClassic worldwide localities
- Emerald Creek, Idaho, USA
- India
- Sri Lanka
Field-hunting tip
Look in metamorphic schist country — that is the host setting where star garnet typically forms. If you start seeing quartz, mica, feldspar in float, you are in the right ground. Field specimens usually show a dodecahedral crystals with inclusions habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Idaho — start trip planning there.
Common questions
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Find star garnet on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
