QuestionAre the words "occlusions" and "inclusions" (which seem to both be used) both correct to describe natural flaws from something within the gemstone?
AnswerThey are technically different, although often interchanged. An inclusion is actually some thing (a different substance) in the stone. In my museum, I have a large flourite tetrahedran that has a Pyrite inclusion.
An occlusion is something that is "in the way". In reality, the pyrite is also an occlusion, but it is not considered such. If you imagine cutting open a geode and expecting to find a hollow center lined with dainty spiked crystals, but it was solid quartz, the quartz is an occlusion, even though it is the exact same material as the dainty spikes would have been.
