Kyanite

Colour	Blue
Mohs hardness	4.5–5 parallel to one axis 6.5–7 perpendicular to that axis
Lustre	Vitreous to white
Streak	White
Crystal system	Triclinic
Transparency	Transparent to translucent
Cleavage	[100] perfect [010] imperfect with 79° angle between
Fracture	Splintery
Specific gravity	3.53–3.65 measured; 3.67 calculated

What is Kyanite?

Kyanite is a typically blue aluminosilicate mineral, found in aluminium-rich metamorphic pegmatites and sedimentary rock. It is the high pressure polymorph of andalusite and sillimanite, and the presence of kyanite in metamorphic rocks generally indicates metamorphism deep in the Earth's crust. Kyanite is also known as disthene or cyanite.

How to identify Kyanite

Lustre: Vitreous to white.
Hardness: Mohs 4.5–5 parallel to one axis 6.5–7 perpendicular to that axis — soft; a knife will scratch it.
Streak: White.
Habit: Triclinic crystal system.

Kyanite value

Based on 100 recent eBay sold listings, a raw / cluster Kyanite typically sells for $4–$20 (about $0.02–$0.06 per gram for raw material). After eBay fees a seller nets roughly $12 on a median piece.

Recently sold	Weight	Sold	Date
Natural Crystal Worry Stone: Choose Gemstone (Crystal Healing Pocket Stone)	—	$5	2026-06-21
Natural Kyanite - Brazil 925 Sterling Silver Pendant Jewelry CP62262	—	$14	2026-06-21
💎 2.56ct 9.5x7.5mm Oval Natural Blue Kyanite - Untreated, Nepal Gemstone	1 g	$5	2026-06-21
349G Rare!! Natural beautiful Blue KYANITE with Quartz Crystal Specimen Rough	349 g	$7	2026-06-21
925 Sterling Silver Ring Oval Kyanite 5x3mm Natural Gemstone Jewelry Size 8	—	$17	2026-06-21
130G Natural Kyanite Cluster Crystal Mineral specimen Freeform Energy Healing	130 g	$16	2026-06-21

Typical recently-sold prices, 2026-06. Condition, size and quality vary widely, so this is an estimate, not an appraisal. See current sold listings on eBay ↗. Full value guide · how we work this out.