Niigataite is a strontium-rich member of the clinozoisite-epidote group, uniquely identified by its distinctive pink coloration caused by its composition. It is primarily found as an accessory mineral in high-pressure, low-temperature metamorphic rocks in Japan. Collectors look for its well-formed prismatic crystals embedded in quartz or schist matrices.
Is this niigataite?
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 niigataite with a known reference. Niigataite sits at Mohs 6-7, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Niigataite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Niigataite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: pink, reddish-pink.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: prismatic crystals, radial aggregates, massive.
Often confused with
Niigataite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside niigataite
Minerals reported to co-occur with niigataite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ca₂SrAl₃(Si₂O₇)(SiO₄)O(OH)
- Mohs hardness
- 6-7
- Density
- 3.5 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Prismatic Crystals, Radial Aggregates, Massive
- Cleavage
- Perfect
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Metamorphic Rocks
- Typical price
- $20-150 per specimen depending on size and quality
Where rockhounds find niigataite
Classic worldwide localities
- Niigata Prefecture, Japan
- Kochi Prefecture, Japan
Field-hunting tip
Look in metamorphic rocks country, the host setting where niigataite typically forms. If you start seeing quartz, albite, calcite in float, you are in the right ground. Field specimens usually show a prismatic crystals, radial aggregates, massive habit, so train your eye for that shape before scanning the outcrop.
Common questions
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Find niigataite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
