CS Book 5_AS-26 Feldspar:Diopside .pdf

Feldspar, Spodumene, and Diopside KEY CONCEPTS Feldspar, spodumene, and diopside are soft gems with The most prized labradorite type is “spectrolite,” a cleavage in two directions, so they req...

Feldspar, Spodumene, and Diopside KEY CONCEPTS Feldspar, spodumene, and diopside are soft gems with The most prized labradorite type is “spectrolite,” a cleavage in two directions, so they require protective settings. phenomenal labradorite with brilliant spectral hues. Feldspars are the most widespread minerals on earth. Small inclusions give sunstone a reddish or golden sheen, while larger inclusions create glittering reflections. The phenomenal moonstone variety includes all adularescent feldspars. Sunstone from Oregon isn’t treated, a feature that producers Moonstone’s adularescence is caused by the scattering of light use as a selling point. by stacked, alternating mineral layers. Kunzite is most commonly light pink, but its most valuable The finest moonstones possess a colorless, semitransparent to colors are intense pink and intense violetish purple. nearly transparent appearance and vivid blue adularescence. The most common cutting style for moonstone is the cabochon. Light-colored or colorless spodumene is irradiated and then carefully heated to produce kunzite’s rosy color, but Moonstone is readily available in modestly priced, calibrated the color—treated or natural—can fade under heat or bright sizes, but it’s rare and much more expensive in fine quality. light. Labradorite’s phenomenal colors are caused by interference of High clarity and lack of treatment make chrome diopside an light reflecting off the gem’s layered structure. effective emerald alternative. Key Terms Blue sheen—Trade term for a highly prized, vivid blue Goldstone—An imitation of aventurine feldspar made of adularescence displayed by the finest moonstone. glass that contains small copper crystals. Centipedes—Tiny tension cracks in moonstone that interfere with adularescence and reduce value. 243