If Heated It Kills
German miners called this mineral an 'ore flower'. Medieval alchemists said it was 'the Satan's Stone'. The general public, however, preferred to name it a 'fake emerald'. Though the mineral's official name is fluorite.
A few centuries ago, people thought fluorspar was a mysterious and weird stone. Its outer appearance was very much similar to the ones of rubies, sapphires and other precious gems. How could it be true? The main reason is that this mineral varies in colours greatly. In essence, its shade can be anywhere between lilac, purple, green, pink, blue, or yellow. Frequently found samples are multi-coloured, wherein several shades mix together. Regardless, every single specimen has its own unique colour and distinctive pattern. That is why till the middle of the 16th-century fluorite was often mistaken for one or another mineral.
Another distinguishing feature of this stone is that it glows once heated. Alchemists who attempted to investigate this property - all died fast. As the legends say, those poor people were losing their teeth and hair while suffering from bone destruction. And the experiments they held usually ended in explosions and fires. In the end, medieval scientists came to think that it was the devil himself who was guarding the stone's secret. They gave up on trying to recover gold from calcium fluoride and became fearful of the stone. Such rumours were heavily supported by numerous sorcerers and wizards. Their customers were eager to approach them since they had an evil mineral in-store - the one that could kill other people.
In Ancient India, fluorite was greatly honoured. The country's philosophers claimed the mineral encompassed the experience of superior civilisations, which would help people to progress. In East Asia, locals still believe fluorite can change its owner's fate drastically.
The fear towards the mineral had lasted until the very end of the 18th century. Back then a Swedish chemist let a wide audience know that the tragedies of the past were caused by a poisonous gas - fluorine - that fluorite emits if heated or in reaction with acid.
During the Second World War, the mineral became a strategic raw material the Soviet Union used to build up its defence capacities. Fluorite was also considered the best material for making glass for night vision equipment, and it can still be found in some of the most expensive cameras.
Despite fluorite heavily resembling gemstones, it is of no value to jewellers. Due to its low durability, neither it can be used to fake precious stones. Though some dishonest sellers nonetheless keep selling imitations of emeralds made of green fluorites.