The size of the opal bits in the micro sized shards are between 0.35mm - 0.25mm, and are all white opal. This opal provides a very awesome glitter type effect when used in tubing. The material is small, but much larger than powdered and very useable in glass. Can also be used in resin or any other clear application. Our created opal is inert and won't dull or react to the chemical solutions. So get creative! Sold by the gram.