Howlite turquoise is a substitute turquoise made of dyed howlite, a borate mineral. Howlite is porous, like turquoise. In its natural form it is white to grey, as shown in the image to the right.
Its light color and porous nature allows howlite to takes on dye very easily, as exhibited in the howlite turquoise beads to the left. In fact, howlite is used to imitate other gemstones, including lapis. We suspect that as a result it is under appreciated. In our eye, howlite can be beautiful by itself and without the aid of any enhancements.
Howlite has grey veins that have a pattern similar to, but not identical with, turquoise matrix. It you suspect that howlite turquoise is being sold as the real McCoy, study the matrix. If it is grey and thin, you might be holding dyed howlite. In our experience, most howlite turquoise is coming from China, and it is usually being sold honestly as a turquoise substitute. Since the suppliers do not seem to be misrepresenting their product, we suspect that when howlite turquoise is misrepresented in this country as turquoise, it is usually being done so knowingly by the seller. We have noticed, however, that the imitators are getting much better at getting the matrix color closer to that found in turquoise.
Howlite is not particularly hard, but it is hard enough to hold up under normal jewelry use. Most howlite is mined in California and much of that is shipped to China where labor is cheaper to be used in gemstone substitutes.