The imagery goes as follows:
- Onyx (including snowflake obsidian)
- Agate (mineral form, slices and jewellery)
- Chrysoprase (mineral form, jewellery and tumble stones)
- Chalcedony (druzy, jewellery and mineral)
Just from looking at these you can immediately tell that they could sell for a high price to the rich and travellers.
Do the workers sell the minerals to tradesmen who produce the finery before sales men buy them and increasing the price tenfold? Or do the workers give the minerals to their wives who refine it down before selling it on to tradesmen who produce the jewellery? These are questions that I will have to answer before drafting my city out.