JASPER, an opaque close-grained variety of quartz, variously tinted, but usually either red or brown,—the colour being due in the former case to the presence of peroxide of iron, and in the latter to the same oxide in a hydrated condition. Frequently the colour is not uniform, and if the tints be disposed in stripes or bands the mineral is termed riband jasper. A brown jasper occurring in nodules, and exhibiting variations of tint arranged in zones, is termed, from its locality, Egyptian jasper. Although the term jasper is now restricted to such varieties of quartz as present opacity, it is certain from the descriptions of classical writers that their jasj>is or ίασπις was a stone of considerable translucency. The original jasper appears to have been green, inasmuch as it is often compared with the emerald and other green objects. Probably the jasper of the ancients included stones which we should now class as chalcedony and agate, while our jasper was then known as the achates. The emerald-like jasper appears to have been a green chalcedony, like the plasma and chrysoprase of modern mineralogists.

See Rev. C. W. King’s Natural History of Precious Stones, 1865.

ישפה, Exod. xxviii, 20; xxxix, 13; and Ezek. xxviii, 13; ἴασπις, Rev. iv, 3, and xxi, 11, 18, 19. The Greek and Latin name, _jaspis_, as well as the English jasper, is plainly derived from the Hebrew, and leaves little room to doubt what species of gem is meant by the original word. The jasper is usually defined, a hard stone, of a bright, beautiful, green colour; sometimes clouded with white, and spotted with red or yellow.