Disco dust is plastic craft glitter, and is not edible.
Diamonds are clear, but plastic craft glitter (even in clear) isn't going to look like a diamond. What are you trying to make?
ADisco dust can't be consumed, but in the OSSAS rule book disco dust could be used only on items that would/could be removed (gum paste brooches that wouldn't be eaten, perhaps.) All that aside, if you look at a diamond it seems to reflect the blues and yellows of the spectrum more than the other colors. This summer, I ordered clear blue and clear gold from Lusterdust.com and perhaps if the surface were painted with super pearl or even edible silverleaf before sprinkling the disco(more clear blue than clear gold) it would give a diamond-like sparkle, if not Swarovski crystal at the very least. HTH!
Thank you, that is exactly what I was looking for!