(subclass Gemstone Mixture) | Economy.kif 6098-6098 | Gemstone is a subclass of mixture |
(subclass PreciousGemstone Gemstone) | Economy.kif 6099-6099 | Precious gemstone is a subclass of gemstone |
(subclass SemipreciousGemstone Gemstone) | Economy.kif 6104-6104 | Semiprecious gemstone is a subclass of gemstone |