Calcium is a highly reactive alkaline earth metal that does not occur in its native form in nature. In a mineralogical context, it is almost exclusively found in compound forms like carbonates, sulfates, or silicates within various geological environments.
Hardness
1.75
Mohs
Luster
Metallic
Streak
White
Transparency
Opaque
Is this calcium?
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 calcium with a known reference. Calcium sits at Mohs 1.75, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Calcium leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Calcium typically shows a metallic luster.
- 4Match the color rangeCompare against the expected color range: silver-white, pale yellow.
- 5Look at form & habitCrystal system: cubic. Typical habit: massive, granular.
All properties
- Chemical formula
- Ca
- Mohs hardness
- 1.75
- Density
- 1.55 g/cm³
- Colors
- Streak
- White
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Cubic
- Crystal habit
- Massive, Granular
- Cleavage
- Perfect
- Rarity
- Rare
- Uses
- Research, Reagent
- Typical price
- expensive
Where rockhounds find calcium
1 mapped spotsField-hunting tip
Field specimens usually show a massive, granular habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Nevada. Start trip planning there.
Common questions
How do you identify calcium?+
Mohs hardness is 1.75. It typically shows a metallic luster. The streak is white. Common colors include silver-white, pale yellow.
Can I find calcium in the United States?+
RockHoundR maps 1 calcium rockhounding spots across 1 U.S. states. The top states are Nevada.
How much is calcium worth?+
Typical asking prices fall in the range of expensive. Quality, size, and provenance can move individual specimens well outside that range.
What is calcium used for?+
Calcium is used in research, reagent.
Find calcium on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
