Brown Agate
Silica var. Chalcedony (Agate) · Semi-Precious Gemstone / Decorative Stone
Crystal System
Trigonal, microcrystalline habit forming massive, nodular, or tumbled smooth shapes
Mineral Group
Silicates, specifically Tectosilicates
Chemical Formula
SiO2
Formation Process
Hydrothermal or low-temperature sedimentary deposition, filling cavities in volcanic and metamorphic rocks
About This Crystal
A smoothly polished, tumbled stone with a rich brown body color, showcasing subtle lighter tonal banding and internal fractures. It has a waxy to vitreous luster and is translucent to opaque.
Physical Characteristics
Brown body color, white streak, no distinct cleavage with a conchoidal fracture, specific gravity around 2.60 to 2.65, and brittle tenacity
Optical Properties
Refractive index ranges from 1.543 to 1.554, doubly refractive with microcrystalline structure, uniaxial positive
Hardness & Durability
Origin Region
Found globally with notable sources in Brazil, India, Madagascar, Uruguay, and the United States
Hardness & Durability
Mohs hardness of 6.5 to 7, making it durable and suitable for everyday jewelry wear with good resistance to scratching
Care & Maintenance
Easy to maintain; can be cleaned with warm soapy water and a soft cloth, avoiding harsh chemical cleaners and prolonged direct sunlight
Rarity & Value
Very common and widely accessible, highly affordable, often tumbled or carved into ornamental items
Special Characteristics
Microcrystalline structure often displaying fine banding, slight translucency under strong light, and internal fractures acting as light traps
Lore & History
Historically used by ancient civilizations for amulets, seals, and ornamentation to provide protection and grounding. In modern crystal healing, it is associated with stability, grounding, and the Root Chakra.