Arfvedsonite in Quartz
Arfvedsonite-Quartz Rock · Collector Mineral / Decorative Stone
Crystal System
Monoclinic (Arfvedsonite needles) within Trigonal (Quartz matrix); the item is fashioned into a polished sphere (orbicular habit).
Mineral Group
Silicates (Inosilicates - Amphibole Group for Arfvedsonite; Tectosilicate for Quartz)
Chemical Formula
Na3(Fe2+,Mg)4Fe3+Si8O22(OH)2 (Arfvedsonite) + SiO2 (Quartz)
Formation Process
Igneous/Magmatic crystallization; forms in highly alkaline plutonic rocks like nepheline syenites and pegmatites during the late stages of magmatic differentiation.
About This Crystal
A polished dark sphere featuring a mottled, swirling pattern of deep charcoal-black to bluish-black mineral patches (Arfvedsonite) embedded in a light grey to white translucent matrix (Quartz). The surface is smooth with a vitreous to slightly waxy luster.
Physical Characteristics
Color: Black, grey, white. Streak: Greyish-blue (arfvedsonite). Cleavage: Perfect amphibole cleavage at 56 and 124 degrees (hard to see in polished sphere). Specific Gravity: ~2.65 (Quartz) to ~3.4 (Arfvedsonite). Non-magnetic. Brittle.
Optical Properties
Sub-metallic sheen in Arfvedsonite inclusions; Quartz is transparent to translucent. Arfvedsonite shows strong pleochroism (dark blue-green to brownish-yellow) under microscopic examination.
Hardness & Durability
Origin Region
Primarily Greenland (Ilimaussaq complex), Russia (Kola Peninsula), and Canada (Mont Saint-Hilaire). Forms in alkaline igneous rocks.
Hardness & Durability
Mohs 5.5 - 6 (Arfvedsonite) vs 7 (Quartz). The composite nature makes it moderately durable but prone to scratching by harder materials. Wearability is good for decorative objects.
Care & Maintenance
Clean with warm soapy water and a soft cloth. Avoid harsh chemicals and ultrasonic cleaners which may penetrate micro-fractures in the matrix. Store away from harder stones to prevent surface scratching.
Rarity & Value
Uncommon. Values are based on the intensity of the black mineral patterns and the quality of the polish. Often confused with Astrophyllite or Nuummite by collectors.
Special Characteristics
Arfvedsonite often displays a signature flash of blue or silver brilliance (chatoyant-like) when rotated under direct light, distinguishing it from other dark amphiboles.
Lore & History
Discovered in 1823 and named after Johan August Arfwedson. In metaphysical lore, it is believed to be a stone of manifestation and spiritual growth, associated with the throat and third eye chakras for enhancing intuition.