H Beam Piper's sunstones

[quote=The Fuzzy Papers] Some fifty million years ago there had existed a marine life form, something like a jelly fish. As these died they sunk into the sea bottom ooze; sand covered the ooze and pressed it tighter and tighter; until it became glassy flint, and the entomed jelly fish little beans of dense stone. Some of them by some ancient biochemical quirk, were intensely thermoflourescent; worn as gems they glowed from the wearer's body heat. On Terra a single pollished sunstone was worth a small fortune. [/quote] These are mined from sandstone and I like them for treasure items. Might adapt them for the next "In the Minzii Marketplace" article.