Jasper
Quartz (Microcrystalline) var. Jasper · Semi-Precious Gemstone / Lapidary Material
Crystal System
Trigonal; Microcrystalline (Cryptocrystalline) aggregations typically appearing massive, grainy, or in nodular habits.
Mineral Group
Silicates (Tectosilicate subgroup)
Chemical Formula
SiO2 (with Fe2O3 and other impurities contributing to color)
Formation Process
Primarily Sedimentary or Hydrothermal. Formed when silica-rich fluids permeate through volcanic ash or sedimentary rock, consolidating into a dense, opaque mass with iron oxide and other mineral impurities.
About This Crystal
An opaque, microcrystalline variety of quartz exhibiting an earthy, grainy, or waxy luster. Color varies from reddish-brown to mustard yellow due to iron inclusions. Surface shows a pitted, vuggy texture with tiny sparkling crystalline druse visible in the recessed pockets.
Physical Characteristics
Color: Opaque yellow to reddish-brown; Streak: White; Cleavage: None; Fracture: Conchoidal to uneven; Specific Gravity: 2.58–2.91; Tenacity: Brittle; Fluorescence: Generally None.
Optical Properties
Refractive Index: Approx. 1.54 – 1.55; Birefringence: None (aggregate); Pleochroism: None; Luster: Vitreous to greasy on fracture, waxy when polished.
Hardness & Durability
Origin Region
Globally distributed; notable sources include India, Brazil, Madagascar, USA (Oregon, Idaho), and Australia. Found in sedimentary environments or as hydrothermal replacements in volcanic rocks.
Hardness & Durability
Mohs Hardness: 6.5 – 7. Moderate to high toughness. Highly stable and excellent for all jewelry types including daily wear rings.
Care & Maintenance
Hardy stone; clean with warm soapy water and a soft brush. Resistant to most household chemicals but should be protected from harsh acids. Store separately to prevent scratching softer stones.
Rarity & Value
Common; Very affordable. Value is determined by patterns, color saturation, and unique pictures formed by inclusions. Rarely treated, though some varieties may be dyed.
Special Characteristics
Often contains micro-vugs or cavities (geodes) filled with secondary quartz crystals. The grainy appearance in the image suggests a 'brecciated' or 'silicified siltstone' type of jasper.
Lore & History
Historically known as the 'Supreme Nurturer' across many cultures. Used since antiquity in seal stones, amulets, and jewelry. Associated with grounding and protection in traditional crystal lore.