Howlite has a monoclinic crystal system and is in the mineral class of hydrous borates. Its coloring is white with gray streaks. It is found as nodules embedded in clay of borax deposits in California. Nova Scotia has similar, but smaller nodules in gypsum beds.
Howlite has a soft structure and is easily dyed. The most common coloring for those purposes is blue, trying to appear to be turquoise. For many years, it was substituted for and sold as turquoise, but generally is now marketed with the name of Turquenite (or derivitives). Some claim that the dyed versions carry the same properties for healing as Turquoise. While there may be some similarities, generally I have found them to both be quite different.