Hi Bob, Howlite is a basic calcium boron silicate. Orthorombic.
Prismatic crystals. White. Subvitreous luster. Smooth fracture.
No cleavage. Hardness 2-3.5. Unimpressive in it's native state,
howelite is frequently dyed blue and makes a convincing
substitute for turquoise. Generally the color will fade and is
only on the surface. As it quite soft damages easily, good
substitute fo turquoise but not Lapis. Win