In response to your statement:
the source in Bolivia has been revealed and many beautiful natural ametrine specimens in their natural state have made it to market. It is the only mine in the world that produces this combination of citrine and amethyst within the same quartz crystal straight from the ground in an untreated state.
I would respectfully like to correct you on the above statement.
Although Bolivia is the major commercial source of Ametrine on
today’s market, it does occur naturally at various locations here in
the southern Appalachian Mountains. When it is found, it is of very
high quality with good color saturation. I have faceted several gems
from it and I personally like the color better than the South
American rough. It tends to be much darker than all but the most
expensive imported material with which it compares very favorably. I
have often heard the single source statement as made by you and would
like to correct it so others might know the facts.