Govlit ( howlite ; English Howlite ) - a mineral , calcium borosilicate. Hardness 3.5. The mineral is gray-white with brown and black veins and a silky sheen. Sometimes howlite, in addition to cryptocrystalline masses, occurs in the form of small crystals, which can be seen in ultraviolet light (crystals are highlighted in white). The mineral is named after its discoverer, Canadian geologist Henry Howe. The color of pure gowlite is white or gray; samples with brown and black veins are often found. In ultraviolet light, tiny, barely visible to the naked eye crystals of howlite sometimes glow with a yellowish or whitish light.
| Says | |
|---|---|
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| Formula | Ca 2 B 5 SiO 9 (OH) 5 |
| Physical properties | |
| Color | White gray |
| Trait color | |
| Shine | Silky |
| Hardness | 3,5 |
| Density | 2.5—2.6 g / cm³ |
| Syngonia | Monoclinic |
Govit is easily painted in blue tones and therefore is often used as an imitation of turquoise . The imitation is so accurate that sometimes unscrupulous dealers knowingly give out painted howlite for real turquoise. Cabochons and bead balls, small figures are made from govlite. Their polished surface glistens like porcelain . The main deposits are located in Nova Scotia ( Canada ). Gowl is also found in California .
The natural color of gowlite is unattractive, therefore this mineral is widely used in jewelry artificially painted in blue-green tones, in the form of imitation under turquoise. Sometimes howlite is painted in red, imitating in this case corals. The imitations are so accurate that it is worthwhile to purchase products from a more expensive and rarer turquoise with the prior consultation of a gemologist or in places that are not in doubt about the possible sale of falsification.
Unpainted (rarely) and mainly painted howlite is used to make small figures, beads, pendants and inserts in jewelry.