Howlite and white turquoise are often confused as being the same material, but there are some key differences between the two.
What is Howlite?
Howlite is a mineral first discovered in Nova Scotia in 1868 by Henry How, a Canadian chemist, geologist and mineralogist. Chemically, howlite is a hydrated calcium borosilicate hydroxide (Ca2B5SiO9(OH)5). It is white with fine grey or black veins running through it. The veins make it resemble turquoise, which is how it got the nickname "white turquoise." However, true turquoise is a hydrated phosphate mineral, not a borosilicate.
Howlite is relatively soft, rating 3.5 on the Mohs hardness scale. It can be easily dyed and is often treated with blue dye to better imitate turquoise. The dyed howlite is marketed as "turquenite" and is popular for jewelry making because it provides the look of turquoise at a lower cost. Undyed, natural howlite is also used to make jewelry, carvings and other decorative objects.
What is White Turquoise?
True turquoise is a hydrated phosphate mineral containing copper and aluminium. It ranges in color from sky blue to greenish blue, caused by traces of iron. The finest turquoise has an intense, uniform color. Turquoise is relatively soft, rating 5-6 on the Mohs scale.
White turquoise is not actually turquoise at all. Rarely, white buffalo turquoise may also be found. This is natural turquoise that formed without the iron impurities, resulting in a white color rather than blue. White buffalo turquoise is extremely rare. The vast majority of what is marketed commercially as "white turquoise" is howlite.
How to Tell the Difference
The key identifiers between howlite and white turquoise are:
- Veining patterns – Howlite has distinctive grey veining while turquoise does not. However, sometimes the veining in howlite is obscured by dye.
- Hardness – Howlite is relatively soft while turquoise is slightly harder. White turquoise that can be easily scratched is likely howlite.
- Weight – Howlite is lighter than turquoise. White "turquoise" that feels unusually light is likely howlite.
- Composition – True turquoise contains copper while howlite does not. Lab testing can definitively identify the minerals.
- Price – White turquoise that is very low cost is invariably howlite, while natural white buffalo turquoise is rare and expensive.
So, howlite is commonly dyed to imitate turquoise, and white turquoise jewelry is almost always howlite rather than true turquoise. Natural white buffalo turquoise is very rare. Examining veining, hardness, weight and price are clues to identifying whether a white turquoise is really howlite or the genuine article.
