Howlite is a naturally occurring mineral, a white or light gray stone that forms within the earth. The confusion about whether it is man-made stems from the fact that it is almost always treated or dyed for commercial purposes. This calcium borosilicate hydroxide mineral is a legitimate geological material. Its porous nature and soft texture make it an ideal candidate for alteration, leading many consumers to question its authenticity when they encounter the vibrant, artificially colored versions in the marketplace.
The Natural Formation of Howlite
Howlite is classified as a borate mineral, meaning its chemical structure includes boron. Specifically, its composition is calcium borosilicate hydroxide. This mineral typically forms in evaporite deposits, which are sedimentary rock layers created when mineral-rich water bodies evaporate in arid or semi-arid environments.
It does not often form distinct crystals but instead occurs as irregular, massive nodules that have been described as resembling a head of cauliflower. The natural color is milky white or light gray, usually featuring a web-like pattern of fine gray, black, or dark brown veins. These veins are not always present but contribute to its marble-like appearance when they are visible.
The mineral is relatively soft, with a rating of approximately 3.5 on the Mohs scale of hardness. This low hardness means the stone can be easily scratched, which is why it is often used for carving and ornamental purposes. Howlite was first discovered in 1868 near Windsor, Nova Scotia, by chemist Henry How, after whom the mineral was named.
Addressing the Man-Made Confusion
The widespread confusion about Howlite’s origin is directly related to its commercial treatment and use as an imitation stone. While the mineral itself is natural, the vibrant colors seen in jewelry are manufactured. Howlite is exceptionally porous, meaning it readily absorbs liquids, making it an excellent material for dyeing.
The vast majority of Howlite sold is not in its natural white state. It is most frequently dyed a vibrant robin’s egg blue or blue-green to imitate Turquoise. This dyed material is sometimes sold under deceptive names such as “turquenite” or “blue howlite.”
The same dyeing process is used to create imitations of other gemstones, including deep red for Red Coral or dark blue for Lapis Lazuli. The issue is not that the base material is synthetic, but that the color is artificial and sometimes misrepresented as a more precious stone to the consumer.
Identifying Authentic Howlite
The most straightforward way to identify authentic, untreated Howlite is by its color and veining. Natural Howlite should be a chalky white or light gray color with fine, naturally occurring gray or black veins. If a stone is any color other than this—such as blue, red, or purple—it has been dyed.
A simple test to confirm the presence of dye is to use acetone, such as nail polish remover, on an inconspicuous spot. Rubbing the stone gently with a cotton swab soaked in acetone will cause the dye to bleed onto the swab if the stone is colored Howlite. Genuine, untreated Howlite will not release any color.
Physical characteristics can help distinguish Howlite from synthetic materials like plastic or resin. Genuine Howlite, as a mineral, should feel cool to the touch and possess an opaque, dull luster. Additionally, synthetic imitations often display a uniform color and unnaturally consistent vein thickness, whereas the veins in natural Howlite are typically more irregular and web-like.