You can turn a diamond into a weapon and also a good source for RS gold sell.
IMG Source: thersmg
Make lots of diamond tips and you will gain RS gold
The Diamond bolts are made from the combination of Adamant bolt and Diamond bolt tips which it can also enchanted to make Diamond bolt (e) that is powerful enough to defeat boss monsters. You can effectively make more RS gold just by cutting diamonds into tips. Before buying the necessary materials you need to check out their RS gold price in Grand Exchange and test out the profits you can make.
Buy tons of diamonds in Grand Exchange; put some of the diamonds in the bank. With a chisel in your tool belt, withdraw some diamonds. When you chiseled the diamond, you will gain 12 tips. Chiseled the entire diamond you have. Once you chiseled the entire diamond especially in your storage, start selling them in Grand Exchange to make more Rs gold.