Runite ore can be obtained through the Mining skill in various places throughout Old School RuneScape by mining a runite rock. It requires level 85 Mining and grants 125 Mining experience. The ore can be smelted with 8 coal through the Smithing skill to form a runite bar, which can then be smithed into various rune weapons and armour.
Runite ore is the most difficult ore to obtain as it is usually found in the Wilderness or other high-risk locations, has very few available rocks to mine from, and it has an exceptionally long respawn time of 12 minutes, prompting most players to switch worlds frequently while mining.
Monster Combat level Quantity Rarity Corporeal Beast 785 20 (noted) King Black Dragon 276 1 Dark beast 182 1 (noted) Zulrah 725 2 (noted) Lizardman shaman 150 3–5 (noted) Cerberus 318 5 (noted) Abyssal Sire 350 6 (noted) Rune dragon 380 3–5 (noted) Gargoyle 111 1 Brutal Black Dragon 318 3 (noted) Grotesque Guardians 248&228 3–6 (noted)
As of 17 July 2014 and according to the Boss Pets and Spawn Rates update:
|“||Spawn rates of pretty much everything in Old School will now be consistent throughout all worlds...[and] resources and monsters now spawn at a standardised rate throughout all worlds regardless of how many people are currently online.||”|
— Mods Alfred, Ash, John C, Mat K, Reach, Ronan & Weath
That means runite ore spawns at a standardised spawn rate, which is 12 minutes after it was last mined, no matter how many players are on a world. Whether it's zero or 2000 players in a single server, all ore across the game will respawn at the same rate.
Other way of obtaining
Another way of obtaining runite ore is through the Motherlode Mine. With a Mining level of 85 or higher, one can wash pay-dirt and have a small chance of receiving runite ore along with 75 experience. Also, this can be done at 82 Mining utilising the dragon pickaxe special. It is also possible to obtain runite ore at 75 Mining, but this only applies in blast mining, where you get a 10+ mining boost.