*** RARE *** Rarely offered on Catawiki *** Very nice .... HUGE piece of hand-cut and polished.....Dumortierite with a beautiful deep blue color and a weight of more than half a kilo ! You can see traces of BLACK TOERMALINE ( pic: 3 ) Mined in the Ambositra / Fianaransoa area in Madagascar. Dimensions: Height: 85 mm Width: 65 mm Thickness; 45 mm Weight: 507 grams !!!! Photo's were taken with studio light. EXTRA INFORMATION: Blue Dumortierite is little known and is sometimes mistaken for Sodalite lazurite or even Lapis lazuli. Because those stones are also beautiful blue. Still, it is worth getting to know Dumortierite better. It is in some ways very different from Sodalite or Lapis lazuli. Rough Dumortierite is often found encased in quartz. It is then called Dumortierite quartz. Dumortierite is a very spiritual stone and is called the 'stone of patience'. Due to its calming appearance, the Dumortierite gives peace and overview. The stone is also called Go-with-the-flow stone. In gemstone therapy, Dumortierite is mainly used because of its positive influence on the endocrine system, especially on the thyroid gland when it works too slowly. The Dumortierite owes its name to the French fossil scientist Eugène Dumortier, who discovered the mineral. The sometimes used name Dumorturite is a mistake. Physical characteristics Dumortierite tumbled stones The Dumortierite is a silicate. The green and blue hues are caused by contained iron and especially titanium. The red and gray tones are due to the contained manganese. Composition: (Al, Fe, Ti)7 [O3 | BO3 ] (SiO4)3] + Mn Hardness: 7 - 8.5. Aggregates have hardness 7, crystals have hardness 8.5 Gloss: glass shine, silk glass, sometimes dull Transparency: opaque Fracture: uneven, shell-shaped, brittle Cleavage: good Density: 3.26 - 3.41 Crystal system: rhombic Will be shipped insured and with Track & Trace