Refining

Refining

Description	Gain a chance to find gems while smithing.
Scroll
	Scroll of Refining
Slot	Gloves (6) Boots (6)
Source	Enchanting#Scrollcrafting
Level	34
Silver	400
Rune Amount	40
Rune Type	Air, Earth, Fire, Cosmic
Experience	1,800

Refing adds a chance when Smithing to find gems by 0.02% per action while mining. The first Refining buff has an additional 0.02% chance and a tiny chance to gain gems depending on the base smithing time.

Formula

The chance to find a random gem per action is calculated using this formula:

$GemChance={\frac {{\frac {baseActionTimeMS}{500}}+refining*100+100}{500000}}\times 100\%$

Without Refining no gems drop when smithing.

Level	Image	Bar	Base Time	Buff - Gem Chance
				0	1	2	3	4	5	6
1		Bronze	6s	-	0.042%	0.062%	0.082%	0.102%	0.122%	0.142%
15		Iron	12s	-	0.045%	0.065%	0.085%	0.105%	0.125%	0.145%
30		Gold	20s	-	0.048%	0.068%	0.088%	0.108%	0.128%	0.148%
50		Mithril	30s	-	0.052%	0.072%	0.092%	0.112%	0.132%	0.152%
60		Adamantite	44s	-	0.058%	0.078%	0.098%	0.118%	0.138%	0.158%
85		Runite	90s	-	0.076%	0.096%	0.116%	0.136%	0.156%	0.176%
90		Stygian	106s	-	0.082%	0.102%	0.122%	0.142%	0.162%	0.182%

The following table shows the distribution for random gems:

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