Item#23: Turmalin/ Tourmaline

Turmalinul este un boro-silicat cu compozitie variabila care cristalizeaza in sistemul trigonal. Apare in cantitati mici alaturi de roci magmatice precum granitul, dar si alaturi de roci metamorfice sau sedimentare (de asemenea in mici cantitati). In imagine este prezentata varietatea negra, bogata in fier denumita Schorl. Are forma prismatica, duritate mare pe scara Mohs (7 – 7.5).

Tourmaline is a boro-silicate with variable chemical composition and it forms in the trigonal crystal system. It occurs in small qunatities with igneous rock (like the granite) or sedimentary or metamorphic rocks. You can see in this images the black iron rich variety, the Schorl.

The photos can be used provided the source is acknowledged.

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One thought on “Item#23: Turmalin/ Tourmaline

  1. Pingback: BATUAN METAMORFOSA | Omeld Tambang

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