Citrine is a variety of quartz whose colour ranges from a pale yellow to brown, due to ferric impurities. This crystal is formed when the mineral Amethyst is exposed to intense heat from a natural source, this exposure to the heat transforms the Amethyst into Citrine. So, should that heat process not have occurred, the crystals would have been found as violet Amethysts. Naturally formed Citrine is a very rare occurrence, making it a very desirable and costly crystal. However, Citrine can be created unnaturally by heating

Amethyst to high temperatures in a furnace, this is referred to as 'Heat Treated'. Most of the Citrine found for sale in the market place will have been heat treated due to how rare the natural occurrence is.

You will receive the pictured crystal measuring 2cm long  and it will be sent in a lovely little black velvet lined and labelled box

Many sellers may make weird mystical claims for this type of crystal.
I do not work like that and merely love it for its beauty!