Charoite: properties, varieties and value factors

Key properties

Chemical formula	(K,Na)5(Ca,Ba,Sr)8(Si6O15)2(Si4O9)(OH,F)·11H2O (mineral charoite)
Crystal system	Monoclinic
Mohs hardness	5-6
Toughness	Fair
Refractive index	1.550-1.559
Birefringence	0.0090
Optic character	AGG (massive rock); the pure mineral is biaxial positive (+) (mineral)
Specific gravity	2.54-2.78
Cleavage	None in the aggregate (mineral has micaceous parting)
Fracture	Splintery to granular; fibrous layers can split
Habit	Massive, swirled fibrous aggregates forming a decorative rock (charoitite) with aegirine, feldspar and tinaksite
Lustre	Dull to pearly on fracture; silky on fibrous faces; polish: Vitreous to waxy (silky sheen from the fibrous structure)
UV fluorescence	Inert to weak patchy red in LW; inert in SW
Pleochroism	None (massive aggregate)
Cause of colour	Not definitively established; the purple of charoite is attributed to impurity/defect centres (possibly trace Mn-Fe) rather than a classic chromophore
Typical inclusions	Black aegirine-augite sprays, orange-brown tinaksite streaks, whitish-green feldspar patches, occasional canasite - the rock's signature swirl pattern
Stability	Stable to light; heat and chemical resistance not fully determined - treat gently
Heat sensitivity	Undetermined; avoid torches and ultrasonic
Care and cleaning	Warm soapy water safe; NEVER ultrasonic (vibrations split the fibrous layers); steam risky
Birthstones	None
Availability	Scarce - one known source; export and mining conditions fluctuate
Recognition	Impossible to mistake: swirling lilac-purple with black and orange spatters; sometimes called the lilac stone

Varieties

Charoite

Colour	swirled lavender to deep purple with black, white, grey and orange-brown patterning
Transparency	translucent to opaque
Clarity type	n/a (ornamental rock)
Phenomena	occasional chatoyancy/silky sheen from aligned fibres
Appearance	Turbulent lilac-to-violet swirls threaded with jet-black sprays and warm orange streaks - one of the most unmistakable ornamental stones; polish has a pearly silky quality.
Trade names	lilac stone (early trade name) • charoitite (rock name) • Siberian lilac (marketing)
Misnomers	none established; dyed howlite and reconstructed material are sold as fake charoite
Typical sizes	large blocks yield big cabs, carvings and spheres; beads common
Cutting styles	Cabochons, carvings, beads, inlay; occasionally chatoyant cabs
Key separations	vs sugilite: sugilite is uniform purple (no swirls or orange tinaksite), higher RI about 1.60-1.61; vs purple fluorite: perfect cleavage, H 4, bands; vs dyed howlite or marble: dye sits in cracks and lacks fibrous silkiness; vs lepidolite: scaly mica structure, softer
Sources (localities)	Russia only - Sakha Republic (Yakutia), Murun (Chara) massif, Aldan Shield, Siberia
Availability	Scarce; fine patterned material with strong chatoyancy hardest to source
Market notes	Prices modest for beads but rising for top carving rough; single-source risk; fakes (dyed and reconstructed) increasing
Care notes	No ultrasonic ever; warm soapy water and soft brush; store away from harder stones
In short	Charoite is the single-source Siberian lilac rock: swirling purple fibrous charoite peppered with black aegirine and orange tinaksite. RI about 1.55 aggregate, SG about 2.6-2.7, hardness 5-6. Cut as cabs, beads and carvings; never ultrasonic.

Size (ct)	USD per carat	Tier	As of
1.00–20.00	$1.00 – $12.00	commercial to fine	2026-10-26
20.00–200.00	$3.00 – $25.00	fine carving rough	2026-10-26

Retail market survey, per carat unless noted. Ranges describe what commercial to fine stones trade at; exceptional stones and provenance premiums sit above them.

Sources

GIA gem encyclopedia · mindat.org · Wikipedia

Data compiled and fact-checked against gemmological literature, October 2026 (JDMIS gem reference). Properties are ranges accepted in gemmological practice; individual stones vary.

Key properties

Varieties

Charoite

Sources

See also