Amethyst – Heating can remove unwanted brownish inclusions in some amethysts or lighten the color of overly dark stones .
Ruby – Heating can remove purplish coloration rendering a more pure red color . The process can also remove “ silk ” ( minute needle – like inclusions )
HEAT TREATMENT
– the exposure of a gem to high temperatures for the purpose of altering its color and / or clarity .
Amethyst – Heating can remove unwanted brownish inclusions in some amethysts or lighten the color of overly dark stones .
Ruby – Heating can remove purplish coloration rendering a more pure red color . The process can also remove “ silk ” ( minute needle – like inclusions )
Pale sapphires that were once discarded in the mining process were treated to a desirable color of blue when heated in a controlled environment .