Mixed Minerals — Marin Mineral

Mixed Minerals
October 9, 2025 · 14 specimens

R517 - Mangano Calcite on Calcite sold

Huanggang Mine, Inner Mongolia, China
Small Cabinet - 7 x 6 x 6 cm

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Horizontally grown, parallel crystals of pink Mangano Calcite grown across the back and sides of a larger white scalenohedral Calcite crystal. Unusual and aesthetic! Ex. Len Pisciotta collection.

R518 - Green Beryl sold

Nasarawa Egon, Nasarawa, Nigeria
Small Cabinet - 9.3 x 1.2 x 1.2 cm

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Doubly-terminated green Beryl crystal from recent finds in Nigeria. Glassy with deep green horizontal color banding. Complete all around with a smooth, flat terminations. Weighs 25.91 grams.

R519 - Cadmium Smithsonite on Quartz $225 available

Monte Cristo Mine, Rush, Marion Co., Arkansas, USA
Miniature - 5.0 x 3.5 x 2.5 cm

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Vivid yellow cadmium rich Smithsonite across a matrix covered by glassy clear Quartz crystals.

R521 - Azurite $2,500 available

Touissit, Morocco
Miniature - 3.8 x 1.8 x 0.7 cm

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Lustrous, doubly-terminated Azurite crystal from the Touissit Mine. Complete all around and undamaged with very slight etching along the two narrow prism edges.

R522 - Benitoite $2,500 available

Gem Mine, San Benito Co., California, USA
Cabinet - 11 x 6 x 2.5 cm

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Schist matrix loaded with gemmy, cornflower-blue Benitoite crystals. The crystals reach 1.4cm in size and show partial etching. These are somewhat tabular crystals and I love how many stand up on edge on the matrix. Lots of great crystals on this one!

R523 - Grossular sold

Stifle Memorial Claim, Georgetown, El Dorado Co., California, USA
Cabinet - 10 x 8 x 4 cm

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Rare colorless Grossular crystals from a small find made in 2018 near Georgetown. The specimens were found in an approximately 3 meter long lens in Serpentine that was completely mined out (Len Pisciotta pers. comm.). These have been analyzed as nearly pure end member Grossular with the crystals occurring in bunches or on massive white Grossular. This specimen features and shallow open vug lined with 3-4mm crystals. This deposit is featured in the November-December 2019 Mineralogical Record magazine. Specimen was collected by Len Pisciotta and one of his best from the find.

R524 - Calcite $250 available

Pugh Quarry, Wood Co., Ohio, USA
Small Cabinet - 6 x 3.5 x 3.5 cm

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Sharp, complete six-sided Calcite crystal with a small cluster of crystals attached to the lower backside. Translucent to transparent with rich golden coloration. Undamaged.

R525 - Spinel $400 available

Kajiado Co., Kenya
Small Cabinet - 7.5 x 4 x 3.5 cm

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Fine deep blue crystals of Spinel in white Calcite with Phlogopite mica. There are numerous crystals present, the largest is 8mm tall (the portion exposed from the matrix). Kajiado Co., is located in southern Kenya along the border with Tanzania and near Mt. Kilamanjaro.

R526 - Spinel $220 available

Kajiado Co., Kenya
Miniature - 4.5 x 3 x 1.8 cm

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Fine deep blue crystals of Spinel in white Calcite with Phlogopite mica. There are numerous crystals present, the largest is 6mm. Kajiado Co., is located in southern Kenya along the border with Tanzania and near Mt. Kilamanjaro.

R527 - Gold sold

Mother Lode, California, USA
Thumbnail - 1.5 x 1.1 x 0.8 cm

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Gold crystals from California's Mother Lode Gold zone. Good crystals showing all around. Weighs 2.10 grams (value of the Gold alone is approximately $310).

R528 - Calcite on Conichalcite sold

Mina Ojuela, Mapimi, Durango, Mexico
Small Cabinet - 6.5 x 4 x 2.3 cm

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Old specimen of sparkling clear Calcite crystals atop bright green Conichalcite. The Conichalcite on this one has especially good green color.

R529 - Clinozoisite $500 available

Hashupa, Shigar Valley, Pakistan
Miniature - 4.7 x 1.6 x 0.5 cm

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Glass-like single Clinozoisite crystal from Pakistan. Well terminated and highly transparent. Complete all around and undamaged.

R530 - Prehnite $350 available

Merelani Hills, Arusha, Tanzania
Miniature - 3.6 x 3 x 3.0 cm

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Outstanding, sharp cluster of blue Prehnite, with large individual crystals. Crystallized Prehnite is uncommon worldwide with most Prehnite found as botryoidal masses. The best crystals are known from the Jeffrey Mine in Canada and here at Merelani. Merelani Prehnite is mostly yellow with these blue Prehnites being much less common and blues of this quality with such good crystal form even more so. These are also color change, producing different shades of blue in indoor versus outdoor lighting.

R531 - Cyanotrichite sold

Grandview Mine, Coconino Co., Arizona, USA
Thumbnail - 2.5 x 2.0 x 1.5 cm

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Beautiful bright blue acicular crystals Cyanotrichite lining a vug, with some green Malachite adding color contrast. Because the crystals are fragile, I love that these are well protected in the vug! It's like a miniature Cyanotrichite geode. These specimens are very hard to come by now as the locality is now part of Grand Canyon National Park. This old copper mine began operation in 1892, stopped operation around 1907, and became a part of the national park system in 1940. The specimen is likely over 100 years old!

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