Yellow quartz, known as false topaz, Bohemian, occidental, Indian,
or Spanish topaz, resembles the real topaz in color, but is softer,
lighter, different in crystallization and cleavage, and in electrical
properties.
In color, this stone varies from the lightest yellow to orange-red and
brown.
Most of the yellow quartz comes from Brazil, and much of it is changed
to yellow by burning amethyst and smoky quartz.