Red beryl is one of the rarest gemstones in the world, found exclusively in Utah, USA. Formed in fluorine-rich rhyolite under highly specific geological conditions, it differs from other beryls typically associated with pegmatites. Its scarcity, small crystal size, and complex formation make it a highly sought-after material among collectors and gemologists.

Maw-sit-sit is a rare metamorphic rock from Myanmar, often associated with jade. Composed mainly of kosmochlor and chromian jadeite, it is distinguished by its mottled texture and vivid green color. Formed under high-pressure, low-temperature conditions in subduction zones, it represents a complex material at the intersection of mineralogy and gemology.