Gemstones
Spican flame gems
Wadi gemstones
A gemstone (or jewel) is any of a number of mineral forms, typically crystalline, some of which are greatly valued as precious stones in many cultures. These gemstones include diamond, emerald, ruby, sapphire, topaz, Rigelian flame gems, and tourmaline.
By the 23rd century, it was possible to synthesize most of these in any quantity required, rendering them essentially valueless, though many are still traded for low-end commercial use such as Spican flame gems. In 2267, Korob attempted to bribe members of the USS Enterprise crew with such stones; his flawed research led him to believe that they would be swayed by such a fortune. (TOS: "Catspaw")
The Betazoid gift box sent to Deanna Troi in early 2364 contained numerous jewels that were spilled out as soon as the box had delivered its message. (TNG: "Haven")
The Folnar jewel plant, a plant native to Folnar III, secretes a resin that hardens into a gemstone. (TNG: "Dark Page")
Among the items and artifacts Vash secured in the storage locker of the assay office aboard Deep Space 9 in 2369 was a hand full of assorted gems. (DS9: "Q-Less")
During First Contact with the Wadi, they presented a bag of jewels to Quark as their wager in dabo. (DS9: "Move Along Home")
Bajoran villagers presented Chief Miles O'Brien with a plate full of gemstones when he was temporarily chosen as their Sirah. (DS9: "The Storyteller")