Jewelry Lovers

The display by malachite in its captivating symphony of greens is repeated by rhodochrosite (Greek rhodon = rose; chros = flesh color) on an equally grand scale in rose-red alternations. The latter is no less prolific in original designs of convoluted banding; with unflagging inventiveness it imprints its patterns in light and dark pink tones. It, too, originates through weathering, of manganiferous limestones. For rhodochrosite is also a carbonate of manganese, MnCO₃, occurring in the form of botryoidal or pipelike aggregates, whose individual microscopically tiny stalky crystals possess trigonal symmetry and exhibit the easy cleavage of all carbonates. Known only since the Second World War, rhodochrosite seems little suited to the strenuous demands of daily use in jewelry because of its low hardness. But thanks to its delicate colors it is enjoying increasing favor in handmade handicrafts. The marbled structure of layers, varying from white to glowing raspberry red or dark rose-red nuances, implants unique color compositions and designs on the large surfaces of ashtrays, bowls, or paperweights. The best quality is obtained in San Luis (Argentina) from a silver mine apparently abandoned in the thirteenth century by the Incas, where rhodochrosite has since grown up from the floor toward the roof as stalagmites. This proves that it can be no older than seven hundred years. In recent times the United States has also come to the fore by producing wonderful clear transparent crystals.

Similar to rhodochrosite is the darker, wine-red rhodonite, a manganese silicate (CaMn₄[Si₅0₁₅]) with a minor iron and calcium content. The cryptocrystalline aggregates, whose individual units crystallize in the triclinic system, form compact masses with prismatic cleavage. Rhodonite was formerly found in the Urals and was much prized in Russia as a stone both for use in jewelry and for making Easter eggs for gifts. Today Sweden, Australia, California, and Vancouver Island (Canada) are the most important producers of this patrician material. The fine shades of deep rose-red to bluish-red tones and the black veins of manganese oxide together create those animated scenes from which springs the enchantment of this ornamental stone for those endowed with imagination. In the larger oval rhodonite plaque on the bottom of the color plate opposite, for example, a plesiosaur (marine reptile) may be clearly seen in a typical Jurassic landscape—about 1 so million years ago—stalking out of a swamp, while above him on a branch an archaeopterix (primitive bird) spreads its wings.

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Precious Gemstone, Rhodochrosite and Rhodonite: Inca Rose and Peach Blossom