What is howlite?
howlite,white turquoise is a calcium borosilicate hydroxide, generally white or gray in color. Due to its gray and black veins similar to those of turquoise, it is often sold under the trade name of “white turquoise” and dyed to imitate green turquoise or blue lapis lazuli.
Howlite properties
What is howlite made of? Howlite is a calcium borosilicate hydroxide. It is generally white or translucent or gray in color with brown, gray or black veins, very fine in texture, with a glassy luster and a Mohs hardness of 3 to 4 out of 10 (rather soft). Diamond, for example is a 10 and talc, the softest mineral, is 1.
The luster is glimmering or sub-vitreous, which means the luster doesn’t quite come up to that of glass. When it is scraped against a harder material, howlite leaves a white streak. Howlite will sink in water, as its specific gravity or relative density is 2.53 to 2.59 times that of water.
Howlite has no cleavage, which means there is no one direction along which the crystal will more easily break. When it is fractured the pieces are uneven or resemble seashells. This is called a conchoidal fracture.
Despite its rarity, howlite is inexpensive when compared to other semi-precious gems and easy to obtain. Its softness makes it easy to carve and polish, and it is often used to make small pieces of jewelry such as beads, whether they be round or other shapes. Howlite is also polished into cabochons, which are domed beads with flat bottoms.
Due to its porous texture and gray and black veins similar to those of turquoise, howlite can be easily dyed to imitate other stones, especially turquoise and lapis lazuli.
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