Mexican Fire Opal Dark 2-10mm Chip - 15-16 Inch Stone Type_Jade Selenite is a crystal formed

Selenite is a crystal formed from the mineral gypsum

It is known for its colors -- dark green and mustardy yellow

Boulder Opal is a golden-brown to dark brown stone

It can even exhibit various colors within the same specimen

blue-greens and greens swirled with yellow-green

Mexican Fire Opal Dark 2-10mm Chip - 15-16 Inch Stone Type_Jade Selenite is a crystal formed[Use Fire Opal description? This Fire Opal contains both Opal and the rhyolitic host material in which it is formed, which provides sufficient hardness for the stone to be cut. The name Fire Opal is derived from the translucent fiery oranges and reds for which the Opal is known, though it also can occur in dark brown and golden colors. Some specimens of Fire Opal produce iridescent flashes and are referred to as Precious Fire Opal or Firmament Stone.]