The stone spirit sends ore to bank for you and gives you a small chance of receiving higher level ore, sent directly to your bank. After each dose of juju mining potion is consumed, a five minute period (one hour for perfect juju mining potion) begins during which each ore mined has a 10% chance of finding a stone spirit.
When you find a stone, you will get a message "A stone spirit appears and offers to carry your next few loads of ore to the bank."
When mining "The stone spirit magics your ore straight to the bank." A swirling colour effect will appear above the player's head and shoulders when this occurs.
In addition to the above, the stone spirit from the perfect juju mining potion also automatically smelts some of the ores you mine and giving you the smithing experience you would have gained from smelting it. Smelt coal provides the same experience as steel bars, but is destroyed. If you mine gold ore and wear Goldsmith gauntlets at the same time, you will gain double exp for the gold ores smelted by the stone spirit. This allows for very fast and effective training in both mining and smithing at the same time.
More than one stone spirit may appear during the window in which the potions effects are active. Up to six stone spirits have been recorded, but in theory, eight or nine are possible.
When the spirit disappears you get the message: "The stone spirit burrows down at your feet."
With the Divination update the ore banking effect was replaced with the ore smelting effect. This was reverted with the release of Prifddinas batch 2 and the smelting effect was added to the perfect juju mining potion instead.
A table of which bonus ores you can get:
|Ore mined\Bonus ore||Copper||Tin||Iron||Silver||Coal||Gold||Mithril||Adamantite||Runite|
|Concentrated coal rocks||No||No||No||No||No||Yes||Yes||Yes||Yes|
|Harmonised coal rocks||No||No||No||No||No||Yes||Yes||Yes||Yes|
|Concentrated gold rocks||No||No||No||No||No||No||Yes||Yes||Yes|
|Harmonised mithril rock||No||No||No||No||No||No||No||Yes||Yes|