Prospecting

Prospector

Description	Increases your chance to find gems by a mysterious amount.
Scroll
	Scroll of the Prospector
Slot	Pickaxe (6)
Source	Enchanting#Scrollcrafting
Level	25
Silver	300
Rune Amount	40
Rune Type	Air, Fire, Cosmic
Experience	1,500

Prospector increases the chance to find gems by 0.02% per action while mining. Unlike Root Digging and Refining gems can be obtained without the enchantment.

Formula

The chance to find a random gem while mining is calculated using this formula:

$GemChance={\frac {baseTime*2+prospector*100+100}{500000}}\times 100\%$

Level	Zone	Base Time	Buff - Gem Chance							Buff 6 - Average Gems per Day
			0	1	2	3	4	5	6
1	Clay Pit	5s	0.022%	0.042%	0.062%	0.082%	0.102%	0.122%	0.142%	25
10	City Outskirts	8s	0.023%	0.023%	0.043%	0.063%	0.083%	0.103%	0.123%	13
20	Village	8s	0.023%	0.023%	0.043%	0.063%	0.083%	0.103%	0.123%	13
30	Desert	12s	0.025%	0.025%	0.045%	0.065%	0.085%	0.105%	0.125%	9.0
40	Underground	12s	0.025%	0.025%	0.045%	0.065%	0.085%	0.105%	0.125%	9.0
50	Hidden Mine	15s	0.026%	0.026%	0.046%	0.066%	0.086%	0.106%	0.126%	7.3
60	Volcano	15s	0.026%	0.026%	0.046%	0.066%	0.086%	0.106%	0.126%	7.3
70	Deep Pit	20s	0.028%	0.028%	0.048%	0.068%	0.088%	0.108%	0.128%	5.5

The following table shows the distribution for random gems:

Gem	Chance
Sapphire	40%
Emerald	30%
Ruby	20%
Diamond	7%
Black Opal	3%