Some old-time customs and cures, persisting in spite of superior smiles and “scientific” derision, have been found to incorporate materials which modern medicine has in its time welcomed into the pharmacopoeia, the checkbook of current remedies. In ancient times, lapis lazuli was used as a “charm” against bleeding of the nose, against inflammation of the eyes, against any kind of hemorrhage. The Egyptians prescribed lapis lazuli 4,000 years before chemists noted the astringent qualities of copper oxide—which is what gives the golden flecks to lapis lazuli.
Malachite
Malachite is a basic copper carbonate, chemically CuCO₃Cu(OH)₂. It can be highly polished and takes its name from the green color of the leaves of the mallow plant, the marsh variety of which gives its name to a popular candy. The stone is used for small boxes and other decorative pieces; well polished, it makes an attractive ring.
Moonstone
Moonstone is a milky-white translucent variety of feldspar, with a pearly lustre.
Feldspar (also felspar, meaning spar of the field) is any of a group of crystalline minerals, made up mainly of aluminum silicates. They are glassy and moderately hard, and are found among igneous rocks. Spar is the name of various shiny materials that break off easily, in chips or flakes. Few of these varieties are used in ornaments, but the even milk-white tone of a good moonstone makes it effective in jewels.
Onyx
Named, because of its pale color, from the Greek word for nail, onyx is a variety of agate. It consists of alternate layers of different colored stone, as can be seen around the edge; this makes it prized for carving, especially in cameos.
Opal
The opal was represented in such variety in early times that the word upala was the general Sanskrit term for a precious stone. The opal comprises a large group of vitreous, translucent silicas, possessing the property of refracting light and then reflecting it in a play of colors. Silica is a dioxide of silicon, chemically Si O₂, a hard glassy mineral that includes quartz and sand as well as opal. According as the compound includes iron, magnesium or other elements, the color of the stone varies.