| Gewicht | 0,1 kg (100 gr) |
|---|---|
| Sales Unit | |
| Minimum order | 200 gr |
| Type | |
| Size | |
| Number | 40 pieces per kg |
| Quality | A |
| Form | |
| Origin | |
| SKU | 6078 |
Dumortierite Tumblestones | A - M/L
Sales unit: Per 100 gr
Minimum order: 200 gr
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Dumortierite tumble stones from South Africa.
Dumortierite
Dumortierite is an aluminium-borosilicate that usually occurs in blue to violet-blue shades, often with a fibrous or granular structure. The stone is named after French palaeontologist Eugène Dumortier, who described the mineral in the 19th century. Due to its striking colour, dumortierite is often used as an ornamental stone and sometimes as an imitation of lapis lazuli.
Major deposits include Brazil, Madagascar, South Africa, Sri Lanka and the United States. Dumortierite forms in aluminium-rich metamorphic rocks and pegmatites. Its chemical formula is Al₇BO₃(SiO₄)₃O₃ and its hardness is between 7 and 8 on the Mohs scale, making it relatively hard and wear-resistant.
Sources:
Mindat.org, Gemdat.org, Wikipedia - Dumortierite
