Tveitite-(Y) is a rare yttrium-calcium fluoride mineral found primarily in granitic pegmatites. It is highly prized by collectors for its distinctive bright white fluorescence under short-wave ultraviolet light, which helps differentiate it from common fluorite.
Is this tveitite-(y)?
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 tveitite-(y) with a known reference. Tveitite-(Y) sits at Mohs 3.5 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Tveitite-(Y) leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Tveitite-(Y) typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: white, colorless, yellowish-white.
- 5Look at form & habitCrystal system: trigonal. Typical habit: rhombohedral crystals, massive.
Often confused with
Tveitite-(Y) vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside tveitite-(y)
Minerals reported to co-occur with tveitite-(y). Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Y,Ca)₅(F,O)₁₁
- Mohs hardness
- 3.5
- Density
- 3.45 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Trigonal
- Crystal habit
- Rhombohedral Crystals, Massive
- Cleavage
- None
- Fluorescence
- Bright White/pale Yellow Under SW UV
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Granite Pegmatites
- Typical price
- $50-300 per specimen
Where rockhounds find tveitite-(y)
Classic worldwide localities
- Tveitdalen, Iveland, Norway
- Hittero, Norway
Field-hunting tip
Look in granite pegmatites country — that is the host setting where tveitite-(y) typically forms. If you start seeing fluorite, quartz, microcline in float, you are in the right ground. Field specimens usually show a rhombohedral crystals, massive habit, so train your eye for that shape before scanning the outcrop.





