This is a rare potassium, sodium sulfate which is almost never found in euhedral, barrel shaped crystals of this size, up to 8 mm in length. The crystals are lustrous and translucent and exhibit a light gray. This is from an early expedition to the salt domes of Iran. This piece, with numerous crystals to about 1 cm, is (i am told) of a superior quality. I have seen only one other of any quality, for sale, from the Zinn collection rarities suite back in 2003. In fact, that piece is still, 8 years later, one of only a very few Iranian examples illustrated on MINDAT: http://www.mindat.org/loc-190502.html

Emplaced on a vein of foliated, purple actinolite are sharp crystals of lustrous, deep green, chromium rich, lawsonite, an uncommon silicate. The crystals reach 1 cm across and some appear to be doubly terminated. 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. This uncommon silicate is 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. 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

Crystals of lustrous, dark green chromium rich lawsonite, to 1.7 cm across, are festooned on both sides of the host matrix. Several crystals appear to be doubly terminated. 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 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. 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

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 1.5 cm, 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.Several crystals appear to be doubly terminated. This particular specimen is the largest good example I saw, and also has a very rich association with the purple actinolite matrix for contrast. 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

Perched high on a ridge of matrix are several , lustrous, dark green crystals of chromium rich lawsonite, an uncommon silicate mineral. The crystals reach 1.2 cm across and a few appear to be doubly terminated. 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 1.2 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. 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

A remarkable new find from the Tucson 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 1 cm, 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.Several crystals appear to be doubly terminated. This specimen has perhaps the sharpest crystals here, with higher luster and sharper edges than most other examples. 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

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

Emplaced on a gray matrix are crystals of pseudocubic, lustrous and translucent, light orangy-yellow colored chabazite, an uncommon member of the zeolite family. The largest crystals reach 1.8 cm in length. A superb and pretty example from this classic locality, examples of which we seldom see on the market today.