Limonite with Druzy Quartz
Goethite/Limonite with Quartz (Silicon Dioxide) · Mineral Specimen
Crystal System
Trigonal/Hexagonal quartz crystals on an Amorphous to Orthorhombic mass
Mineral Group
Oxides / Hydroxides and Silicates
Chemical Formula
FeO(OH)·nH2O (Limonite) + SiO2 (Quartz)
Formation Process
Secondary formation via weathering of iron-rich minerals with silica-rich hydrothermal fluids
About This Crystal
Earthymid-to-dark brown porous matrix covered in tiny, sparkling clear micro-crystals with vitreous luster
Physical Characteristics
Brown streak, no cleavage in mass, conchoidal fracture in crystals, vitreous to dull luster
Optical Properties
Sub-adamantine to dull (Limonite), Vitreous (Quartz); uniaxial positive for quartz crystals
Hardness & Durability
Origin Region
Common worldwide; notable specimens from Iron King Mine, USA, or Morocco
Hardness & Durability
4-5.5 (Limonite) to 7 (Quartz); brittle and prone to crumbling if handled roughly
Care & Maintenance
Avoid water immersion (porosity), clean with soft brush or compressed air, keep dry
Rarity & Value
Common; value depends on aesthetic sparkle and specimen size ($5 - $50 range)
Special Characteristics
Druzy effect (scintillation from many small crystal faces reflecting light simultaneously)
Lore & History
Used historically as a source of iron ore (ochre); associated with grounding and stability in lore