Micro-World Gems & Gemology, Fall 2022, Vol. 58, No. 3

Unusual Purple Fluid in Quartz

This pear-shaped quartz contained several fluid inclusions.
Figure 1. This 27.76 ct pear-shaped double cabochon contained several fluid inclusions with a vibrant purple component. Photo by Annie Haynes; courtesy of Mike Bowers.

Recently the authors examined a 28.93 mm long, 27.76 ct transparent pear-shaped double cabochon rock crystal quartz that contained numerous fluid-filled negative crystals (figure 1). Oddly, some of the negative crystals also hosted a brightly colored purple liquid in addition to what appeared to be a colorless liquid, the two liquid phases being immiscible (figure 2).

Several negative crystals in this quartz contained a bright purple liquid.
Figure 2. Several fluid-filled negative crystals were present in this rock crystal quartz cabochon, a few of which contained a highly unusual brightly colored purple liquid. Photomicrograph by Nathan Renfro; field of view 14.50 mm. Courtesy of Mike Bowers.

Not all of the fluid inclusions within this quartz contained the purple component. However, all of the purple liquid–hosting negative crystals did contain partially healed, limonite-stained fractures intersecting them. This suggests that the purple fluid may have entered the negative crystal cavities through a post-growth or secondary process rather than homogeneous entrapment during growth.

While colored fluid inclusions have been previously reported in quartz—colors that include blue, yellow, and orange (see e.g., Spring 2004 Gem News International, pp. 79–81; Spring 2006 Gem News International, p. 71)—this is the authors’ first observation of a purple fluid trapped within quartz. Unfortunately, Raman spectroscopy to identify the fluid was unsuccessful, as the fluid was too deep in the crystal. While the composition of the fluid is unknown, as well as the conditions under which the fluid entered the quartz, there is no obvious indication that it resulted from an artificial process. However, the possibility of such artificial tampering cannot be ruled out entirely. This fascinating purple fluid inclusion is one of the strangest and most interesting the authors have examined.

Nathan Renfro is manager of colored stone identification, and John Koivula is an analytical microscopist, at GIA in Carlsbad, California.