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.
The probabilities in this section are an estimation based on the data of opening 1,806 bags full of gems, totalling 72,240 uncut gems being obtained.
According to these estimates, a bag could be expected to be around 48,313.74 value of gems on average.