Characteristics of Howlite:

Chemical Name: Calcium borosilicate hydroxide

Formula: Ca2B5SiO9(OH)5

Colors: White

Structure: Monoclinic

Hardness: 3.5

Specific Gravity: 2.6

Refractive Index: 1.58-1.61

Lustre: Subvitreous

Streak: White

Locations: USA, Canada, Mexico, Germany, Russia, Turkey

What is Howlite? 

Popular with collectors, Howlite is generally found in nodules, in which it is usually white with veins of other minerals running through it. it is relatively porous and absorbs dye well, in particular blue dye; when altered in this way, it resembles and is sometimes erroneously sold as, turquoise. Fortunately, it is easily distinguished from turquoise since it is much softer, although it can still be polished. Howlite is found in quantity in Death Valley, California. It was named after the Canadian chemist, Henry How, who discovered it in 1868.