Howlite: Discovered in Canada in 1868, howlite is a relatively recently discovered stone. Howlite is perhaps best known as an imitation stone. In fact, its porous surface and natural white & grey colouring make it ideal for dyeing. Due to the veining pattern similarities, howlite is often used to imitate turquoise, which is why it is also called "white turquoise" even though it is not actually related to turquoise.