Epidote and Jasper Sphere
Catoctin Formation
Page County, Virginia
This specimen measures 6cm in diameter
Epidote Ca2Al2FeOSiO4Si2O7(OH)
Sorosilicates; basic calcium, aluminum, iron silicate
Color and Luster: Yellowish green to brownish black; vitreous; streak colorless to gray
Hardness: 6-7
Cleavage: Perfect, one direction lengthwise
Fracture: Uneven, brittle
Crystals: Monoclinic; usually in long, slender, grooved prismatic crystals that are frequently terminated by two sloping faces; also thick tabular crystals; massive, columnar, divergent, acicular, granular
Chalcedony (var. Jasper) SiO2
Tectosilicates; a variety of quartz (silicon dioxide), often with some iron and aluminum
Color and Luster: clear red to brownish red(Var. carnelian and sard, carnelian and sard in layers (Var. onyx), bright green with spots of red(Var. heliotrope and bloodstone), variegated(Var. agate), banded, agate with moss- or tree- like inclusions(Var. moss agate), apple-green(Var. chrysoprase), variegated and mottled red, yello, and brown(Var. jasper), whitish, dull gray, smoky brown to black(Var. flint), also white to gray, brown, blue, and black; waxy luster, vitreous, dull; streak white
Hardness:7
Cleavage: None
Fracture: Conchoidal, brittle to tough
Crystals: None; chalcedony is a microcrystalline variety of quartz usually occuring as crusts with botyroidal or mammillary forms; or compact, banded
Photo by Lance Kearns
Descriptions taken from
The Audubon Society Field Guide to North American Rocks and Minerals