Lawsonite Var. Chromian
Cabinet, 14.4 x 9.3 x 5.0 cm
Cape Marmari, Grammata Bay, Syros Island, Greece
Ex. Al Ordway

A remarkable new find from the Tucson 2012 show, of green lawsonite crystals (the color induced by chromium), in contrasting matrix with thin veins of purple actinolite and white muscovite.These are lustrous, deep green crystals to 2 cm across, of chromium-rich lawsonite, which is a very uncommon silicate found in good crystals at only a few locales wordlwide. And, never have we seen them with such color! This is from a small find, but it is unclear exactly when it was found and leaked out to the market. Although slightly corroded, several crystals appear to be doubly terminated. CORRECTION NOTED WITH THANKS TO DR. Maarten Broekmans: The “ purple actinolite” you mention in the descriptions, however, is glaukofane or crossite, a sodic amphibole characteristic of high-pressure terranes. This complies with lawsonite being a sodic HP mineral itself, far better than an actinolite would, a calcic (Fe, Mg) amphibole. the silvery white mica is rather paragonite, the Na equivalent of K-muscovite. Also typical for HP settings. Besides that, Cr would color an actinolite stark green too, not purple. In fact, whole (scarcely vegetated) valleys on the island have this bluish-purplish tone over them, an amazing view

Order Now