Howlite, scientifically called a calcium borosilicate hydroxide, is a silicate mineral often used to replicate turquoise. In nature, the stone is white or grey with dark stripes. Although the mineral is often legitimately sold, it is occasionally pawned by dealers as real turquoise, which raises the price considerably.
The mineral was discovered by and named for Henry How, a 19th century Canadian geologist. Initial deposits were found in How’s native Nova Scotia, but have since been uncovered in Southern California as well. The mineral is now generally mined for its use as an imitation stone, although some New Age practices use undyed stones for meditation.
The mineral has a porous structure that allows it to accept dyes uncommonly well. Because of the characteristic streaks found in turquoise, howlite makes an excellent substitute. The Mohs scale hardness of the mineral is only 3.5, considerably lower than the average turquoise hardness of 5 to 6. This rating means that the imitation is more likely to be scratched or fractured than the authentic stone.
Other than this difference, the two stones are nearly identical, and some claim that even jewelers have difficulty telling them apart in absence of ultra-violet (UV) testing. In UV tests, howlite often appears to give off colored fluorescent glows. It also dissolves quickly in hydrochloric acid without causing bubbling, something turquoise will not do.
In recent years, this stone has been used as a substitute for several other minerals. The similarly streaky lapis lazuli is a much darker blue than turquoise, but howlite’s porous surface can soak up enough dye to make a worthy substitute. The mineral also can be dyed to make an excellent imitation of red coral. This last use has caused great happiness among environmental activists, as the harvesting of coral for commercial purposes has shown to cause severe and lasting damage to underwater ecosystems.
According to some meditation forms that use crystals as focus points, undyed howlite can be an excellent means of concentration. Some believe it is highly stress relieving and recommend it as a means of relieving insomnia. Some crystal users suggest that the mineral helps balance calcium levels in the body and acts as an absorbent for negative energy. It is also said to correspond with the Zodiac sign Gemini.
This mineral is often found dyed and carved into figures or jewelry. As a turquoise substitute, it is often less expensive than the real thing. People who enjoy Native American jewelry styles may find the mineral is frequently used instead of traditional stones. Many online merchants carry pieces carved from the mineral, with simple bracelets and pendants available for relatively low cost. Those who are looking for the beauty of turquoise, lapis or red coral, without the expense, should consider this worthy substitute that even professionals may not recognize as unauthentic.