Howlite

Howlite is a fascinating and somewhat notorious mineral in the world of gemology. While it is a distinct, naturally occurring borosilicate mineral with its own unique properties, it is far more famous for its ability to flawlessly impersonate other, much more expensive gemstones—most notably, turquoise.

The mineral was first discovered in 1868 near Windsor, Nova Scotia, Canada. Miners working in a gypsum quarry noticed a strange, harder material interfering with their extraction and brought it to Henry How, a local chemist and geologist. He identified it as a new silico-borate mineral and originally named it “silicoborocalcite.” It was later renamed “howlite” in his honor by the prominent American mineralogist James Dwight Dana.

Formation & Geology

Howlite is primarily an evaporite mineral. It forms in arid, dry environments where mineral-rich lakes or inland seas have completely evaporated, leaving behind vast deposits of borates and sulfates. Consequently, it is almost always found in massive nodules alongside gypsum, anhydrite, and other borate minerals like colemanite or ulexite.

These nodules can range from the size of a marble to massive boulders weighing hundreds of pounds. Because it forms as an opaque, massive aggregate, Howlite almost never occurs in distinct, visible crystals (the only known microscopic crystals were found at the original site in Nova Scotia).

Physical Characteristics

In its natural, unadulterated state, Howlite is an opaque, porcelain-white to milky-white stone. Its most distinguishing visual feature is the presence of striking, fine, web-like veins (matrix) running through it, which are typically black, brown, or silver-gray.

Physically, Howlite is quite soft, possessing a hardness of only 3.5 to 4 on the Mohs scale. This makes it very easy to cut, carve, and polish, but it also means it is highly susceptible to scratching and abrasion in daily-wear jewelry.

The single most important physical characteristic of Howlite for the jewelry trade, however, is its extreme porosity. The microscopic structure of the massive nodules acts like a sponge, allowing the stone to absorb liquids deeply and evenly.

Gemology & Value

This high porosity is what makes Howlite the ultimate chameleon of the gem world. By submersing natural white Howlite in intensely colored dyes, it can be permanently altered to mimic almost any opaque stone.

When dyed a vibrant robin’s-egg blue, its natural black matrix makes it an incredibly convincing and cheap substitute for fine spiderweb turquoise. When dyed deep blue, it mimics lapis lazuli (often sold as “Lapis Howlite”). When dyed bright red, it imitates coral.

While there is nothing wrong with dyed Howlite (it is a beautiful and affordable material), it is frequently sold to unsuspecting buyers as the genuine article. Unscrupulous dealers often market natural, undyed Howlite as “White Turquoise,” a trade name that takes advantage of the fact that true white turquoise is exceptionally rare and valuable.

Metaphysical Properties

In the crystal healing community, natural white Howlite is highly regarded as an incredibly calming stone. It is deeply associated with the crown chakra and the element of air. Practitioners use it primarily to absorb stress, tension, and intense anger (both one’s own and anger directed toward them). It is famously recommended to be placed under a pillow to combat insomnia caused by an overactive mind. It is also believed to teach patience, promote peaceful communication, and facilitate a deep, meditative state.