Red topaz

Red Topaz is a members-only item on the OSRS Grand Exchange in the other category.

In-game examine text: "A semi precious stone."

It has a Grand Exchange buy limit of 11,000 every four hours, a high alchemy value of 120 gp, and item ID 1613.

View on OSRS Wiki

Red Topaz shows an active flip setup with a margin of +24 gp and 84,512 trades over the last 24 hours.

At the buy limit of 11,000 every four hours, max profit per cycle is about 264.0k gp — high margin with healthy liquidity.