Tallonian homeworld
The Tallonian homeworld was an inhabited planet in the Tallonian system. This was the homeworld of a native civilization.
Tallonian crystals originated from the Tallonian homeworld and were considered contraband anywhere but on the planet. A special type of equipment called a type 4 Tallonian microscanner was used to determine the purity of the crystals. (DS9: "Hippocratic Oath")
This planet was only mentioned in dialogue.