RuneScape Classic Wiki
RuneScape Classic Wiki
The main RuneScape Wiki has an article on: Uncut dragonstone
The Old School RuneScape Wiki also has an article on Uncut dragonstone.

An Uncut dragonstone is an uncut gem that is used in the crafting skill. Uncut dragonstones can be cut at level 55 crafting by using it with a chisel, giving 127.5 crafting experience. Dragonstones can then be used to create dragonstone jewelry. The only method of obtaining this gem uncut is to receive a rare drop from the King Black Dragon, Red Dragon, Black Dragon or to trade with another player.

Previously the crystal chest located in Taverley would always yield one uncut dragonstone when used with a crystal key, however the chest was rendered inoperable by a bug which was never fixed.

Dropped by

Monster Combat level Quantity Rarity
Black Dragon 200 1 4Rare
King Black Dragon 245 1 5Very rare
Red Dragon 140 1 5Very rare