Idris flower dust, or simply "Dust", was a very powerful hallucinogenic drug. It needed to be processed for use.
It was illegal throughout the Federation, but on heavily populated Federation worlds it had a street value of up to 4000 credits per kilogram. It was also very popular on Caloron, where it was said to sell like Spican flame gems.
In reference stardate 2/1412 (circa 2273), in the Shadow Market of Daros IV, an Orion drug dealer known only as "The Pharmacist" tried to sell five 10 kilogram lots of Idris flower dust at 1000 credits per kilogram, though he would take 500. Refusing to buy the Dust was grounds for suspicion in the Shadow Market. (FASA RPG module: Orion Ruse)