Niocalite is a rare calcium niobium silicate mineral primarily found in carbonatite complexes. Collectors should look for its distinctive yellow-to-amber prismatic crystals and its characteristically strong bright yellow fluorescence under shortwave ultraviolet light.
Is this niocalite?
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 niocalite with a known reference. Niocalite sits at Mohs 6, 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: light yellow.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: square.
Often confused with
Niocalite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside niocalite
Minerals reported to co-occur with niocalite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ca₇Nb(Si₂O₇)₂O₃F
- Mohs hardness
- 6
- Density
- 3.32 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Square
- Cleavage
- None
- Fluorescence
- Bright yellow under SW UV
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In coarse-grained strontian carbonatite
Where rockhounds find niocalite
Classic worldwide localities
- Oka, Quebec, Canada
Field-hunting tip
Where it forms: In coarse-grained strontian carbonatite. If you start seeing calcite, magnetite, apatite in float, you are in the right ground. Typical habit: square. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify niocalite?+
Where is niocalite found?+
What rocks look like niocalite?+
What minerals are found with niocalite?+
What kind of rock does niocalite form in?+
What is niocalite used for?+
Find niocalite on the map
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