Jasper (Iron-rich Siliceous Rock)
Silicon Dioxide (Microcrystalline Quartz) with Hematite inclusions · Semi-Precious Gemstone / Decorative Stone
Crystal System
Trigonal (Microcrystalline/Cryptocrystalline); Habit is typically massive, granular, or nodular without visible crystal faces.
Mineral Group
Silicates (Tectosilicate subgroup)
Chemical Formula
SiO2 + Fe2O3 (Iron Oxide impurities)
Formation Process
Sedimentary/Hydrothermal; forms when silica-rich fluids permeate porous rocks or volcanic ash, or via chemical precipitation in sedimentary environments.
About This Crystal
An opaque, microcrystalline variety of quartz. It features a dense, granular texture with a waxy to earthy luster. This specimen shows a mottled reddish-brown to tan color due to high iron oxide content, with visible vugs or pits.
Physical Characteristics
Color: Reddish-brown, tan, ochre; Streak: White or brownish-red; Cleavage: None; Fracture: Conchoidal to uneven; Specific Gravity: 2.58–2.91; Fluorescence: Generally inert.
Optical Properties
Refractive Index: ~1.54; Birefringence: None (aggregate); Pleochroism: None; Optical Character: Opaque, meaning it does not transmit light even on thin edges.
Hardness & Durability
Origin Region
Worldwide; notable deposits in India, Russia, Brazil, Australia, and the western United States (e.g., Oregon, Idaho).
Hardness & Durability
Mohs Hardness: 6.5 to 7. Extremely durable and tough due to its microcrystalline structure; lacks cleavage, making it highly resistant to breaking.
Care & Maintenance
Highly stable. Clean with warm soapy water and a soft brush. Resistant to most household chemicals but should be kept away from hydrofluoric acid.
Rarity & Value
Common; value depends on pattern intensity and color. Used extensively in lapidary work, cabochons, and beads. Very affordable as rough mineral specimens.
Special Characteristics
Opaque nature distinguishes it from Agate; the 'pitted' or vuggy surface suggests a host rock with gas bubbles or weathered-out mineral inclusions.
Lore & History
Historically known as the 'Supreme Nurturer.' Used by ancient Egyptians and Native Americans for amulets and tools. Symbolizes grounding, strength, and endurance in traditional lore.