Purple Fluorite 1x2mm Square Rondelle - 15-16 Inch Stone Type_Beryl Yellow Opal is transparent to

Yellow Opal is transparent to opaque

as legend has it

Wood Opalite is a type of petrified wood that has been impregnated with the Silicon Dioxide commonly known as Opal

Smoky Quartz it the national gem of Scotland

Biotite was named in honor of the French physicist Jean-Baptiste Biot

Purple Fluorite 1x2mm Square Rondelle - 15-16 Inch Stone Type_Beryl Yellow Opal is transparent toFluorite is a luminous, soft and glassy stone, sometimes referred to as the most colorful mineral in the world. It is one of the most sought to after minerals among gem and mineral collectors, second only to Quartz. The term fluorescent was inspired by Fluorite, one of the first fluorescent minerals ever studied. It is frequently fluorescent under ultraviolet light, and this phenomenon is thought to be due to impurities of yttrium or organic matter