Rensselaer Union, Volume 7, Number 20, Rensselaer, Jasper County, 4 February 1875 — Chaleedony. [ARTICLE]

Chaleedony.

What boxwood is to the wood-en-Siver —the means without which his est art would be impossible—that chalcedony is to the engraver of gems. Hard without brittleness, susceptible of a'fine and endurable polish, tinted by nature with beautiful and at times strongly-con-trasted hues, or capable of taking on such colors at the hand of man, it has been from the earliest period of art not only the favorite medium but the only possible medium of the gem-engraver’s most striking effects. In its simplest state chalcedony is an unattractive white stone, nearly transparent, and chiefly useful for making spear-heads and ar-row-tips, or their more modern representatives, gun-flints. Sometimes it has a striped or banded appearance, due to alternations of more or less translucent layers, ranging in color from whey white to the white of skim milk, still not very serviceable for gems or jewelry. When strained by metallic oxides, however, chiefly those of iron, it rises to the dignity of gem stone, as sard, carnelian, chrysoprase, etc., which are uniformly tinted brown, yellow, red or green, as agate, onyx, sardonyx, etc., when the colors lie in bands or strata or are separated by layers of white. The natural formation of these flowers of the mineral world is recorded in their substance. Though commonly found in lavas and other igneous rocks, or in the debris remaining from their disintegration, gem stones are substantially an aqueous product, and require the agency of fire simply to develop their fine colors, a step in their production more the work of art thangof nature.