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Pyroxmangite


Pyroxmangite is a calcium manganese silicate. The mineral name reflects its similarity to pyroxene minerals and also it major manganese content (Ford & Bradley, 1913). While all chemically similar, bustamite, rhodonite, and pyroxmangite are distinguished at the atomic scale by their silicate chains. All three are single chain silicates, but with differing repeat lengths along their silicate chains. Pyroxmangite has a repeat of 7 silicate tetrahedra, while bustamite and rhodonite have repeats of 3 and 5 tetrahedra, respectively (Ohashi & Finger, 1978; Pinckney & Burnham, 1988). X-ray diffraction studies readily differentiate these species.

At the Taguchi mine, pyroxmangite forms in veins within metamorphosed manganese skarns. Veins are typically compact massive, but occasionally pockets of neotocite allow for crystal development. The red pyroxmangite crystals, here to 5 mm, were exposed by removal of black resinous neotocite. This is vintage material dating to 1960, when John Patrick supplied this material to Minerals Unlimited. Nice!

Price: $150

Item code: MS1590

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