Massive Quartz with Mica
Quartz var. Rock Crystal with Muscovite inclusions · Mineral Specimen / Decorative Stone
Crystal System
Trigonal crystal system; habit is massive and microcrystalline with grains of mica.
Mineral Group
Silicates (Tectosilicate for Quartz; Phyllosilicate for Mica)
Chemical Formula
SiO2 (Quartz) with KAl2(AlSi3O10)(OH)2 (Muscovite)
Formation Process
Metamorphic or Igneous; typically formed through the cooling of silica-rich magma or the recrystallization of pre-existing rocks under high pressure and temperature.
About This Crystal
An opaque to translucent massive stone displaying a drab greyish-brown body color. It features a dull to earthy luster on weathered surfaces with small, highly reflective metallic-looking flakes of mica scattered throughout.
Physical Characteristics
Color: Grey-brown; Streak: White; Cleavage: None (Quartz), Basal (Mica flakes); Fracture: Uneven to sub-conchoidal; Specific Gravity: ~2.65; Fluorescence: Generally inert.
Optical Properties
Refractive Index: 1.544-1.553; Birefringence: 0.009; No visible pleochroism in massive form; localized sparkly reflections (aventurescence-like) from mica.
Hardness & Durability
Origin Region
Worldwide; commonly found in metamorphic and igneous terrains such as Brazil, USA, and India.
Hardness & Durability
Mohs hardness of 7 for the quartz matrix; mica flakes are much softer (2-2.5); overall durability is high but the surface can be crumbly if weathered.
Care & Maintenance
Clean with warm soapy water and a soft brush. Avoid harsh chemicals that might penetrate the porous surface of a weathered specimen; store separately to prevent scratching softer components.
Rarity & Value
Common; low monetary value as a raw specimen. Value is primarily geological or decorative rather than gemological.
Special Characteristics
Displays small, bright specular reflections from the inclusion of mica flakes within the quartz matrix, creating a subtle sparkly effect when rotated in light.
Lore & History
Quartz has been used since antiquity for tools and talismans. In lore, it is considered a universal healing stone. Mica is historically associated with mental clarity and 'reflection' due to its shiny, mirror-like quality.