Oddly enough, the basically yellow variety of quartz is known as citrine quartz, or simply citrine, despite the fact that generally the color is nothing like lemon yellow. lt was and still is called topaz or topaz quartz as well, because of a similarity in color, much to the detriment of true topaz, which is thus considered more plentiful, and less valuable,
than by rights it should be.

Appearance The color varies from pure yellow to dull yellow, honey, or brownish yellow, sometimes even with a russet tint. As with amethyst, the color is often broken up into patches or bands, although due to its depth of hue, the zoning is less obvious. It has good luster (like amethyst) and is generally very clear and virtually free of inclusions because the amount of raw material available allows for considerable selectivity. It is fashioned into all the styles normal for transparent stones, except the brilliant cut.

Large stones of 10 carats or even more are often seen. Distinctive features Color zoning, where present, may be an aid to recognition. The density of citrine (together) with that of orthoclase) is the lowest for stones of this color and is much less than that of topaz, in particular. Although normally good, its luster is slightly inferior to that of topaz and the latter can show signs of incipient cleavage, never seen in citrine.

As with the majority of quartzes, the interference figure is characteristic, where this can be established. Citrine is far less lustrous than yellow sapphire, which also normally has highly characteristic inclusions. As a rule, however, citrine can only be distinguished from the numerous other yellow" stones by an examination of the physical properties.

Occurrence _ Large quantities of citrine are obtained from Brazil. It is also found in the United States (North Carolina, California), Spain, and the Soviet Union.

Value Quite low, for a secondary gem; less than that of amethyst. Like amethyst, it was much more highly valued in the past than it is today.

Simulants and synthetics It is not imitated; but despite its low value, it is synthesized, like amethyst, on a large scale. The cost of the synthetic version is equal to or only slightly lower than that of the natural gemstone. Amethyst, when heated, assumes the yellow color of citrine.