Grossular garnet is a calcium-aluminum member of the garnet group that typically forms in contact-metamorphosed limestone. It is known for its beautiful range of colors, especially the vibrant green variety known as tsavorite and the orange variety known as hessonite. Look for its characteristic dodecahedral crystal habit when searching in skarn environments.
Is this grossular 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 grossular garnet with a known reference. Grossular Garnet sits at Mohs 6.5-7.5 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Grossular Garnet leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Grossular Garnet typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: green, yellow, orange, brown, colorless, red.
- 5Look at form & habitCrystal system: cubic. Typical habit: dodecahedral or trapezohedral crystals, often with rounded faces.
Often confused with
Grossular Garnet vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside grossular garnet
Minerals reported to co-occur with grossular garnet. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ca₃Al₂(SiO₄)₃
- Mohs hardness
- 6.5-7.5
- Density
- 3.5-3.6 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Cubic
- Crystal habit
- Dodecahedral or Trapezohedral Crystals, Often with Rounded Faces
- Cleavage
- None
- Fluorescence
- Orange Under UV in Some Varieties
- Rarity
- Common
- Uses
- Collector, Gemstone, Lapidary
- Host rock
- Skarn Deposits, Contact Metamorphic Rocks
- Typical price
- $10-100 for specimens, higher for gem-quality faceted stones
Where rockhounds find grossular garnet
1 mapped spotsClassic worldwide localities
- Mexico
- Canada
- Kenya
- Tanzania
- USA
- Russia
Field-hunting tip
Look in skarn deposits, contact metamorphic rocks country — that is the host setting where grossular garnet typically forms. If you start seeing diopside, calcite, vesuvianite in float, you are in the right ground. Field specimens usually show a dodecahedral or trapezohedral crystals, often with rounded faces habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in California — start trip planning there.
Common questions
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Find grossular garnet on the map
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