Some Smokey Quartz (rare) will heat treat to a Yellow/green
Citrine.Here is a list of some Amethyst I am sure of.
Maramba,Brazil Dark Red/Orange to light Yellow
Brezeina,Brazil Dark Browinsh/Orange to light Yellow(straw)
Rio Grande do Sul Dark Red/Orange to light yellow
Aria,Brazil Light yellow
Uruguay Light yellow to some mines Brown/red
Porroacca,Brazil light yellow
Jacobina,Brazil Won't heat treat to Citrine
Pal D'arco,Brazil Won't heat treat to Citrine
Bolivian Won't heat treat to Citrine
Goias,Brazil Won't heat treat to Citrine
Zambian,Africa Limited tests would not make Citrine
Namibian,Africa Limited tests would not make Citrine
Brundi,Africa Limited tests produced light yellow
do Sul,Brazil border Won't heat to Citrine.
Many more I have not yet tested,to include 4 Peaks,Arizona,USA I
suspect will treat Korean(rare),Russian,Madagasgar.Canadian.
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