Altisite is a very rare silicate mineral occurring primarily in the hyper-alkaline rocks of the Kola Peninsula. It typically forms clear or white prismatic crystals within pegmatite veins associated with other unusual alkaline minerals. Collectors prize it as a rare species representative of highly evolved igneous environments.
Is this altisite?
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 altisite with a known reference. Altisite 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: white.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: anhedral grains.
Often confused with
Altisite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside altisite
Minerals reported to co-occur with altisite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Na₃K₆Ti₂Al₂Si₈O₂₆Cl₃
- Mohs hardness
- 6
- Density
- 2.64-2.67 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Anhedral grains
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In the interstices of pectolite crystals in a hyperagpaitic pegmatite
Where rockhounds find altisite
Classic worldwide localities
- In a drill core from the Oleny Stream apatite deposit in the southeastern part of the Khibina alkaline massif, Kola Peninsula, Russia (type locality)
Field-hunting tip
Where it forms: In the interstices of pectolite crystals in a hyperagpaitic pegmatite. If you start seeing kalsilite, nepheline, aegirine in float, you are in the right ground. Typical habit: anhedral grains. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify altisite?+
Where is altisite found?+
What rocks look like altisite?+
What minerals are found with altisite?+
What kind of rock does altisite form in?+
What is altisite used for?+
Find altisite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
