Cryolithionite is a rare lithium-sodium aluminum fluoride mineral that typically forms sharp, translucent to transparent dodecahedral crystals. It was originally discovered in the world-famous cryolite deposit at Ivigtut, Greenland, where it occurred as an inclusion within massive cryolite.
Is this cryolithionite?
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 cryolithionite with a known reference. Cryolithionite sits at Mohs 2.5-3, 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: colorless, white.
- 5Look at form & habitCrystal system: cubic. Typical habit: crystalline.
Often confused with
Cryolithionite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside cryolithionite
Minerals reported to co-occur with cryolithionite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Na₃Li₃Al₂F₁₂
- Mohs hardness
- 2.5-3
- Density
- 2.771-2.774 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Cubic
- Crystal habit
- Crystalline
- Cleavage
- Distinct on {011}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In some granite pegmatites
Where rockhounds find cryolithionite
Classic worldwide localities
- Zapot pegmatite, 25 km northeast of Hawthorne, Fitting district, Mineral Co., Nevada, USA
- Ivigtut cryolite deposit, southwestern Greenland
- Miass, Ilmen Mountains, Southern Ural Mountains, Russia
Field-hunting tip
Where it forms: In some granite pegmatites. If you start seeing cryolite, quartz, fluorite in float, you are in the right ground. Typical habit: crystalline. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify cryolithionite?+
Where is cryolithionite found?+
What rocks look like cryolithionite?+
What minerals are found with cryolithionite?+
What kind of rock does cryolithionite form in?+
What is cryolithionite used for?+
Find cryolithionite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
