Turkestanite is a rare thorium-bearing silicate mineral belonging to the steacyite group. It is typically found in alkaline pegmatites as small, yellow to brownish-yellow tabular crystals and is known primarily for its radioactivity due to its thorium content.
Is this turkestanite?
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 turkestanite with a known reference. Turkestanite sits at Mohs 5.5-6, 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: apple green, dark green, brown.
- 5Look at form & habitCrystal system: tetragonal. Typical habit: euhedral crystals, granular.
Often confused with
Turkestanite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside turkestanite
Minerals reported to co-occur with turkestanite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (K,□)(Ca,Na)₂ThSi₈O₂₀·nH₂O
- Mohs hardness
- 5.5-6
- Density
- 3.36 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Tetragonal
- Crystal habit
- Euhedral crystals, granular
- Cleavage
- Poor on {111}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In alkaline to subalkaline massifs
Where rockhounds find turkestanite
Classic worldwide localities
- Jelisu massif and Dara-i-Pioz massif, Tien Shan, Tajikistan
Field-hunting tip
Where it forms: In alkaline to subalkaline massifs. If you start seeing microcline, pectolite, quartz in float, you are in the right ground. Typical habit: euhedral crystals, granular. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify turkestanite?+
Where is turkestanite found?+
Is turkestanite safe to handle?+
What rocks look like turkestanite?+
What minerals are found with turkestanite?+
What kind of rock does turkestanite form in?+
What is turkestanite used for?+
Find turkestanite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
