Disthene

Disthene, also known as kyanite, was a plentiful ornamental stone found across the Realms.

Description
Disthene cleaved easily but was difficult to facet-cut because it was prone to splitting in unwanted directions. This stone could easily be cleaved making it difficult to cut in facets without splitting. Flawless disthene was difficult to find but came in crystals ranging in color from pale green to dark blue. A typical stone had a base value of 10 gp. Good quality blue facet-grade crystals were the most prized at double the base value for 20 gp.

Powers
Disthene was crushed to powder and used as a material component in, or to make inks for inscribing scrolls of, spells that controlled and shaped fire.