Onyx bolt tips
Onyx bolt tips can be obtained by cutting an Onyx. This requires a Crafting level of 61. Another way of obtaining Onyx bolt tips is by looting them from various monsters.
The Onyx bolt tips are used to fletch Onyx bolts. You need to use the Onyx bolt tips on Runite bolts in order to create the Onyx bolts, this has no requirement.