Burnt citrine, amethyst heated
Citrine is a yellow variant of translucent quartz. The yellow color is caused by trace elements, whereby in particular divalent and trivalent iron play a role.
Citrine is the rarest type of quartz and is one of the few gemstones that occur naturally in yellow. The stone is because of the color named lemons. However, natural citrine rather pale yellow with darker shades than lemon yellow.
Not natural citrine
The pieces on this page are NOT natural citrine! These are pieces of amethyst heated and is also called burnt citrine or amethyst burned. They are easy to distinguish from natural citrine by the dark brown color.