crystallize from the partial melt (such as quartz,tridymite, cristobalite, or mullite). These resultsindicate that the partial melt was cooled rapidly,and the zircon inclusion eventually transformedinto ZrO2 and an Al2O3-SiO2-rich glass, followingthe Be-diffusion treatment. These findings are inagreement with those recently published byRankin and Edwards (2003), who provide an indepth discussion of what happens to zircon crystalsat such high temperatures (see also Butterman andFoster, 1967).Note that the melt created by these highlyaltered inclusions often flows into the surrounding strain haloes. As it cools within the halo, itforms the phases mentioned above and createscrossing fern-like structures that are reminiscentof the structure of devitrified glass (see chart figure C-10). These recrystallized haloes were seenin many of the Be-diffused stones, but they wereparticularly common in the orange, yellow, andpink-orange samples. A Raman spectrum of thesubstance within the halo exactly matched spectrum B in figure 43, indicating that it, too, wascaused by the destruction of zircon.Other types of crystals were seen in many of thesamples tested, but in all cases they were damagedor significantly altered by the treatment, and inmost cases they were visually unidentifiable,shapeless white masses (see chart figure C-28). Wealso saw numerous instances of large gas bubblesthat were trapped in internal cavities filled withwhat appeared to be a transparent glass (figure 44).