Yellow Jasper
Quartz var. Jasper (Microcrystalline Quartz) · Semi-Precious Gemstone / Decorative Stone
Crystal System
Trigonal symmetry; typically appears in massive, cryptocrystalline, or granular habits with no visible individual crystals.
Mineral Group
Silicates (Tectosilicate subgroup)
Chemical Formula
SiO2 (Silicon Dioxide) with FeO(OH) (Goethite) or Fe2O3 (Hematite) inclusions
Formation Process
Sedimentary or Hydrothermal; formed when silica-rich fluids permeate through volcanic ash or sediment, precipitating as microcrystalline quartz over long periods at low to moderate temperatures.
About This Crystal
An opaque, microcrystalline variety of quartz. It features a dull to waxy luster and a mustard-yellow to brownish-yellow color. The specimen appears solid and dense with a smooth, somewhat matte surface texture.
Physical Characteristics
Color: Yellow to ochre; Streak: White; Cleavage: None; Fracture: Conchoidal to splintery; Specific Gravity: 2.58–2.91; Fluorescence: Generally inert.
Optical Properties
Refractive Index: 1.544–1.553; Birefringence: Low (often zero in massive forms); Pleochroism: None; Diaphaneity: Opaque.
Hardness & Durability
Origin Region
Global commonality; notable sources include India, Brazil, Madagascar, South Africa, and the United States (western states). Forms in sedimentary or volcanic environments.
Hardness & Durability
Mohs Hardness: 6.5–7; Toughness: Very high due to cryptocrystalline structure; Stable under most conditions and highly wearable for jewelry.
Care & Maintenance
Clean with warm soapy water and a soft brush. Resistant to most household chemicals but should be kept away from hydrofluoric acid. Ultrasonic cleaners are generally safe.
Rarity & Value
Common; value is determined by the vibrancy of color and interesting patterns. Large specimens are affordable and readily available. Enhancements like dyeing are common in commercial stocks.
Special Characteristics
Opaque nature distinguishes it from other quartz varieties; may show 'landscape' patterns or orbicular inclusions if part of a larger nodule.
Lore & History
Historically used as a 'nurturing stone' by ancient civilizations and for carving amulets. Often associated with the Solar Plexus chakra in modern crystal lore, symbolizing protection and discernment.