|The trade expected pink topaz could be just as inexpensive. It's one thing to coax deep-blue from cheap colorless topaz but another to coax deep-pink from uncommon precious topaz. Topaz transformable into pink stones costs a lot more than topaz transformable into blue ones. |
The reason it costs more is limited supply. Not just any precious topaz, but precious topaz with an essential coloring agent: chromium, the same trace element responsible for red in ruby.
Topaz that can be turned pink seems only to come from Brazil, much of it from one mining locality: Oro Preto.