RuneScape Classic Wiki
RuneScape Classic Wiki
The main RuneScape Wiki has an article on: Ring mould
The Old School RuneScape Wiki also has an article on Ring mould.

A Ring mould is a piece of Crafting equipment used to make rings. This mould needs to be in your inventory when you use a gold bar on a furnace. If a cut gem is also in you inventory, you will have the option of adding the gem to the ring.

This mould can be purchased at the Rommik's Crafty Supplies in Rimmington or at the Dommik's Crafting Store in Al Kharid.

Dropped by

They are dropped by:

Monster Combat level Quantity Rarity
Barbarian 16 1 3Uncommon
Gunthor the Brave 37 1 3Uncommon