Variscite and turquoise are sometimes found within the same geographic area, and they also can have a similar appearance in the rough or when cut into cabochons. As a result there has been some confusion, with variscite sometimes being identified as the more common and familiar turquoise. Vendors with uncertainty have been known to use the name “variquoise” for rough and cabochons of questionable identity.

The minerals have a color range with a slight overlap. Turquoise ranges from greenish blue to bluish green, while variscite ranges from yellowish green to bluish green. People who are familiar with the minerals might recognize yellowish green specimens as variscite, but might not feel confident about bluish green specimens.

Cabochons of the two minerals can usually be separated from one another with standard gemological tests.

• Refractive Index: Turquoise produces a spot refractive index of about 1.61, while variscite has a spot refractive index of about 1.57.
• Spectra: With a spectroscope, turquoise sometimes displays weak bands at 420, 432 and 460nm. Variscite sometimes displays a medium band at 690 and a weaker band at 650nm.
• Chelsea Filter: When viewed through a Chelsea filter, variscite usually has a weak pinkish color.

If you have a cabochon that you suspect might be variscite, many gemologists and gemological testing labs offer a gemstone identification service. Geology.com does not offer that service.