A bag full of gems is obtainable from Prospector Percy's Nugget Shop for 40 golden nuggets. Each bag contains an assortment of 40 noted uncut gems.
The chances of an individual gem being an uncut onyx is 1/100,000,000, as confirmed by Jagex Moderators on their weekly Q&A session.
Percentages
The probabilities in this section are an estimation based on the data of opening 410 bags full of gems, totaling 16,400 uncut gems being obtained.
| Item | Percentage | Price |
|---|---|---|
 Uncut sapphire
|
~49.6% | 455 |
 Uncut emerald
|
~34.8% | 679 |
 Uncut ruby
|
~12% | 1,249 |
 Uncut diamond
|
~3.1% | 2,627 |
 Uncut dragonstone
|
~0.45% | 13,080 |
 Uncut onyx
|
0.000001% | 2,869,312 |
According to these estimates, a bag could be expected to bear around 30,085.96 value of gems on average.