Fluorescent calcite is a popular collector's mineral prized for its intense, vivid response under long-wave and short-wave ultraviolet light. It commonly occurs in rhombohedral or scalenohedral crystal habits and is most frequently found in limestone cavities or as a gangue mineral in ore deposits.
Is this fluorescent calcite?
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 fluorescent calcite with a known reference. Fluorescent Calcite 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: vitreous.
- 4Match the color rangeCompare against the expected color range: white, colorless, yellow, orange, pink, blue.
- 5Look at form & habitCrystal system: trigonal. Typical habit: rhombohedral, scalenohedral, massive, or stalactitic.
Often confused with
Fluorescent Calcite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside fluorescent calcite
Minerals reported to co-occur with fluorescent calcite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- CaCO₃
- Mohs hardness
- 3
- Density
- 2.71 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Trigonal
- Crystal habit
- Rhombohedral, scalenohedral, massive, or stalactitic
- Cleavage
- Perfect rhombohedral
- Fluorescence
- Bright red, orange, or pink under UV light
- Rarity
- Common
- Uses
- Collector, Lapidary
- Host rock
- sedimentary limestones, hydrothermal veins, and metamorphic marbles
Where rockhounds find fluorescent calcite
7 mapped spotsClassic worldwide localities
- Franklin, New Jersey, USA
- Terlingua, Texas, USA
- Mexico
- China
- Pakistan
Field-hunting tip
Where it forms: sedimentary limestones, hydrothermal veins, and metamorphic marbles. If you start seeing willemite, fluorite, barite in float, you are in the right ground. Typical habit: rhombohedral, scalenohedral, massive, or stalactitic. Train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Indiana, Arizona, Missouri. Start trip planning there.
More fluorescent calcite photos
Common questions
How do you identify fluorescent calcite?+
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Can I find fluorescent calcite in the United States?+
What rocks look like fluorescent calcite?+
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Find fluorescent calcite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
