Concentrated gold rocks can only be found in the Living Rock Caverns located underneath the northern part of the Dwarven Mine. They require a Mining level of 80 to mine ore from and give 65 experience per ore mined. There are only 4 concentrated gold rocks in the game; they are in the northwest, northeast, southwest, and southeast corners of the cavern.
Concentrated gold rocks will give 1-2 gold ores at a time. The message "you manage to mine two gold ores!" will appear in the chatbox (not filtered) when this happens. This works in addition to the chance of receiving an extra ore if wearing Varrock armour or if boosted by the effects of a shooting star. This increases the possible ore mined to up to 4 at a time, with an overall increase in the chance of finding multiple ores. Gems cannot be obtained from this type of rock.
Players can gain around 62, 000 Mining experience an hour from mining concentrated gold rocks at level 80 Mining; around 70, 500 experience an hour at level 89 and up to 80, 000 experience an hour at level 99 Mining. Those who are looking to be more efficient when mining concentrated gold rocks should superheat at the same time, this means a player can gain Smithing and Magic experience with no loss in experience per hour in Mining. In addition to this, players can choose to use the Superheat Form Seren-prayer to maximise AFK-ability of the concentrated gold rocks, but without gaining the extra magic experience. This, in combination with a relatively high prayer bonus (wearing the Soul Wars cape and Dragon Rider amulet will help greatly, but are not necessary), can be used with around 1 prayer renewal potion per hour. To increase the amount of experience gained, players should wear the goldsmith gauntlets reward from the Family Crest quest.
A concentrated gold deposit recently replenished.
With the removal of the world switching timer, some players choose to stay by the southern most mining spot out of reach of the living rock creatures and hop worlds whenever the concentrated gold rock collapses. This is far safer for those with lower Defence and Constitution levels as well as faster for those with slow connections who can't handle the lag on popular worlds.