It belongs to the quartz family.

Combining the blue of the sky with the red of blood (of Christ or of the martyrs), amethyst became from the Renaissance an episcopal stone, symbol of humility. It adorned the crosses of the inquisition.

Its crystals are always implanted on a rocky substratum. Heating amethysts to temperatures of 470 to 750 degrees, turns their color to light yellow, reddish-brown, green (prasiolite) or colorless. The purple color is attributed to the presence of iron linked to strong irradiation. Amethyst deposits are found mainly in Brazil, Madagascar, Uruguay, Burma, the United States etc....

Amethyst has a hardness of 7 on the Moshs scale.

And don't forget, all stones are fragile! even diamond....