Howlite is a mineral with a hardness of 4 out of 10 on the Mohs scale of mineral hardness [?]. These Monoclinicly structured gems are made of hydrated calcium borosilicate, their full chemical compound being C2B5SiO9(OH)5.
Howlite an opaque, massive mineral used for ornamental and utilitarian articles. is a rarity for collectors
It has a monoclinic tabular crystal system with a subvitreous luster. The most common occurrence is in the form of a cauliflower.
Howlite is found in borate deposits, with most ornamental pieces found from various sites in California (USA) and Mexico.
It occurs as opaque white, and may be porcellanous. but also transparent, snow white, sometimes with black or brown veins, rarely colorless. It can be easily dyed as it is very porous.
When colored with blue dye, howlite is used to imitate turquoise and lapis lazuli. This can be easily detected by a deep orange or brownish-yellow fluorescence once the dye has been removed. Names include "imitation turquoise," "synthetic turquoise,"
Howlite was discovered by gypsum miners near Windsor, Nova Scotia in 1868, who then called the attention of Canadian geologist and mineralogist Henry How.
Howlite is used as material for small carvings or jewellery parts. Because of its porous texture, howlite can be easily dyed to imitate other minerals, especially turquoise, because of the similarity of the veining patterns. The dyed howlite is marketed as turquenite.