Sandstone
Sedimentary Arenite (Quartz-rich) · Decorative Stone / Industrial Mineral
Crystal System
Amorphous/Granular habit; constituent grains are typically Trigonal (Quartz)
Mineral Group
Silicates (as a rock type), specifically a Clastic Sedimentary Rock
Chemical Formula
SiO2 (Primary) with variable Fe2O3 (Iron oxide) and CaCO3 (Calcium carbonate) cement
Formation Process
Sedimentary: Formed via the accumulation, compaction, and cementation of mineral grains (lithification) at low temperature and pressure
About This Crystal
An opaque, earthy specimen with a gritty surface texture. It exhibits a brownish-tan color with a matte, non-reflective luster and a granular, clastic appearance consistent with lithified sand grains.
Physical Characteristics
Color: Tan to brown; Streak: White (on hard surface); Cleavage: None; Fracture: Granular/Uneven; Specific Gravity: 2.2 - 2.8; Fluorescence: Generally inert
Optical Properties
Opaque; individual grains may exhibit vitreous luster under magnification; no significant pleochroism or birefringence in bulk form
Hardness & Durability
Origin Region
Globally ubiquitous; notable architectural sandstones from the United States (Utah/Arizona), United Kingdom, and India
Hardness & Durability
Mohs hardness: 6 to 7 (for individual quartz grains), but the bulk rock durability depends on the strength of the cementing mineral; can be friable
Care & Maintenance
Avoid acidic cleaners if carbonate-cemented; clean with soft brush and distilled water; keep away from oils which may stain the porous surface
Rarity & Value
Common; low monetary value as a single small specimen; primarily valued in bulk for construction or as a geological teaching tool
Special Characteristics
High porosity and permeability; may show bedding planes or cross-stratification in larger specimens
Lore & History
Historically used as a primary building material for ancient monuments such as Petra; traditionally associated with grounding and stability in folk lore due to its earthy origins