A 'perfect' ring is made by crafting a 'perfect' gold bar into a ruby ring. It is needed in the Family Crest quest. The 'perfect' gold bar is made by smelting a 'perfect' gold ore. For details on where to mine it, go to the Family Crest quest guide.
The ring is given to Avan in the quest in exchange for his part of the crest.
Although you can make more, after or during the quest, having more than required is essentially useless. The ring can be worn, but it offers no stat bonuses. It cannot be enchanted into a Ring of forging.
- The P in 'perfect' ring is not capitalised because all items in Old School RuneScape use ucfirst capitalisation, wherein the first letter of a string is capitalised, but the rest is not.