Uncut diamond

Uncut Diamond is a free-to-play item on the OSRS Grand Exchange in the other category.

In-game examine text: "This would be worth more cut."

It has a Grand Exchange buy limit of 10,000 every four hours, a high alchemy value of 120 gp, and item ID 1617.

View on OSRS Wiki

Uncut Diamond shows an active flip setup with a margin of +19 gp and 1,291,351 trades over the last 24 hours.

At the buy limit of 10,000 every four hours, max profit per cycle is about 190.0k gp — high margin with healthy liquidity.