Sandstone
Arenite · Mineral Specimen / Sedimentary Rock
Crystal System
Amorphous/Variable (Granular); typically lacks a macro-crystalline structure but composed of mineral grains like quartz (Trigonal).
Mineral Group
Silicates (as a rock-forming mineral aggregate)
Chemical Formula
SiO2 (predominantly) with varying amounts of Fe2O3 and Al2O3
Formation Process
Sedimentary; formed through the process of lithification involving the compaction and cementation of sand-sized mineral grains or rock fragments.
About This Crystal
A clastic sedimentary rock with a gritty texture. It appears tan to brownish-yellow with a dull, earthy luster and an opaque transparency. It shows a rounded, water-worn cobble shape.
Physical Characteristics
Color: Tan, beige, or yellow-brown; Streak: White to sandy; Cleavage: None; Fracture: Granular or uneven; Specific Gravity: 2.2–2.8; Fluorescence: Generally none.
Optical Properties
None (Opaque); Individual quartz grains within may show vitreous luster and double refraction under a microscope.
Hardness & Durability
Origin Region
Globally ubiquitous; notably found in the Grand Canyon (USA), sandstone formations in Australia, and the Sahara Desert.
Hardness & Durability
Mohs hardness: 6-7 (based on quartz content), but varies depending on the strength of the cementing material. Brittle toughness.
Care & Maintenance
Wash with warm soapy water. Avoid harsh acids which may dissolve carbonate cements. Store separately from softer stones to avoid scratching them.
Rarity & Value
Common; very low market value for raw specimens. Value increases if it contains rare fossils or unique banding (like Wonderstone).
Special Characteristics
Highly porous and permeable; may show distinct bedding planes or cross-bedding in larger outcrops. Often contains iron oxide staining (limonite/hematite).
Lore & History
Historically one of the most important building materials for ancient architecture (Petra, Pyramids, Cathedrals). In lore, it is believed to be a stone of creativity and cohesion.