Black Moss Opal, from Australia, is a milky-white to brownish colour with dark greenish moss-like inclusions. Moss opal is also known as Dendritic Opal, for the tree-like shape of the inclusions. Sadly - it has none of the spectacular play of color that one might hope for from an opal from Australia, which makes it common opal, but is still a handsome stone for all of that. Opal is defined as an amorphous mineraloid comprised of hydrated silicon dioxide - aren't you glad you asked!
10mm x 14mm Approx. 15 on 8 inch (20.32 cm) strand. (strand)