Amethyst
Locality:Amatitlán, Eduardo Neri Municipality, Guerrero, Mexico
(https://www.mindat.org/loc-7318.html)
Formula:SiO2
Colour:Violet - purple
Lustre:Vitreous
Hardness:7
Specific Gravity:2.65 - 2.66
Crystal System:Trigonal
A variety of Quartz
