Every spider species has limits to its range; every place has a limited list of spiders that live there.
Turquoise is composed of hydrated copper and aluminum phosphate. It forms when circulating water alters other aluminum-rich rocks in desert environments.
Some citrine actually began as purple amethyst, but heat from nearby molten rock changed it to a warm yellow color.
The presence of water in the mineral structure allows geologists to determine the temperature of the rock at the time the opal formed.
Sapphire is any form of corundum that is not red, as red varieties are called rubies.
Peridot is type of olivine, and comes in various shades of green, from light to a brilliant olive green.
Ruby originates from metamorphic rock, and is a variety of the mineral corundum, second only to the diamond in hardness.
When light enters the stone, it is bounced back and forth between these layers before it exits as the glowing moon-like effect we see.
Emerald is another variety of beryl. It is surprisingly common for emeralds to contain flaws and veins of chemicals called inclusions.
Diamond is a form of carbon with a tightly bound crystalline structure that originates deep inside the Earth.
Aquamarine is a variety of the mineral beryl. Beryl generally forms inside granites as magma (molten rock) cools deep inside the Earth.