Properties
Amethyst is a violet variety of quartz. Color can range from pale lilac to deep purple. Amethyst has a hexagonal crystal structure, meaning that its crystals have six sides. It is a popular gemstone used in jewelry and has been prized for its beauty for centuries. Amethyst has a hardness of 7 on the Mohs scale (Mohs), making it relatively hard and durable.
Cares
Amethyst can be safely cleaned with warm soapy water. Ultrasonic cleaners are usually safe except in the rare instances where a stone is dyed or treated by fracture filling. Steam cleaning is not recommended, and amethyst should not be subjected to heat.
References:
https://en.wikipedia.org/wiki/Amethyst
https://www.crystalvaults.com/crystal-encyclopedia/amethyst
https://www.minerals.net/mineral/amethyst.aspx
https://geology.com/minerals/amethyst.shtml