sedimentary
Jasper with Epidote Vein
Silicon Dioxide (SiO2) with Calcium Aluminum Iron Silicate (Ca2(Al,Fe)3(SiO4)3(OH))
Hardness: 6.5-7 (Jasper), 6-7 (Epidote); Color: Dark reddish-brown base with a green central band; Luster: Vitreous to waxy; Structure: Microcrystalline; Cleavage: None/Conchoidal fracture; Specific Gravity: 2.58-2.91.
- Hardness
- 6
- Color
- Dark reddish-brown base with a green central band
- Luster
- Vitreous to waxy
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Physical properties
Hardness: 6.5-7 (Jasper), 6-7 (Epidote); Color: Dark reddish-brown base with a green central band; Luster: Vitreous to waxy; Structure: Microcrystalline; Cleavage: None/Conchoidal fracture; Specific Gravity: 2.58-2.91.
Formation & geological history
Formed through the process of hydrothermal replacement or sedimentation of silica-rich fluids. The green epidote band often indicates secondary fluid flow through fractures in the host jasper rock, occurring over millions of years in volcanic or metamorphic environments.
Uses & applications
Primarily used for lapidary work, jewelry making (cabochons), river rock landscaping, and as a pocket stone or collectible for geological hobbyists.
Geological facts
Jasper is a variety of chalcedony that gets its color from iron impurities. The presence of a distinct green band like this is often referred to by collectors as 'Unakite-like' or 'banded jasper,' though Unakite specifically requires pink orthoclase.
Field identification & locations
Identify in the field by its extreme hardness (will scratch glass) and smooth, water-worn texture if found in riverbeds. Common in glacial till across the Midwest USA and mountainous regions globally. Collector tip: wet the stone to reveal the true vibrancy of the hidden colors.
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