Huntite is a soft, chalky carbonate mineral that often occurs as fine-grained, snow-white earthy masses. It is frequently found in sedimentary lake deposits or as a secondary mineral in caves and is highly prized by collectors for its striking white color and intense fluorescence under ultraviolet light.
Is this huntite?
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 huntite with a known reference. Huntite sits at Mohs <3, 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: dull.
- 4Match the color rangeCompare against the expected color range: white, lemon white.
- 5Look at form & habitCrystal system: trigonal. Typical habit: massive, chalk-like, powdery aggregates.
Often confused with
Huntite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Luster reads dull on Huntite and vitreous on Magnesite.
How to tell apart: Luster reads dull on Huntite and vitreous to pearly on Dolomite.
How to tell apart: Luster reads dull on Huntite and vitreous; pearly on cleavages and {0001} on Calcite.
Often found alongside huntite
Minerals reported to co-occur with huntite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Mg₃Ca(CO₃)₄
- Mohs hardness
- <3
- Density
- 2.696 g/cm³
- Colors
- WhiteLemon white
- Streak
- White
- Luster
- Dull
- Transparency
- Translucent
- Crystal system
- Trigonal
- Crystal habit
- Massive, chalk-like, powdery aggregates
- Cleavage
- None
- Rarity
- Common
- Uses
- Industrial, Collector
- Host rock
- Filling vugs and coating fractures in rock; as flowstone and incrustations in caves
Where rockhounds find huntite
Classic worldwide localities
- Ala-Mar deposit, Currant Creek district, and the Gabbs mine, Gabbs district, Nye Co., and the Nevada Magnesite and Snowball deposits, White Pine Co., USA
- Chief Consolidated mine, Eureka, Eureka Co., Utah, USA
- Kalkar quarry, Santa Cruz, Santa Cruz Co., California, USA
- Line Pit, Lancaster Co., Pennsylvania, USA
- Tea Tree Gully, South Australia
- Katherine, Northern Territory, Australia
Field-hunting tip
Where it forms: Filling vugs and coating fractures in rock; as flowstone and incrustations in caves. If you start seeing magnesite, dolomite, aragonite in float, you are in the right ground. Typical habit: massive, chalk-like, powdery aggregates. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify huntite?+
Where is huntite found?+
What rocks look like huntite?+
What minerals are found with huntite?+
What kind of rock does huntite form in?+
What is huntite used for?+
Find huntite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
