Gemstone treatment
Sugar-Acid Treatment
Darkened blue to black color can appear concentrated in porous zones and cracks. Surface may look unnaturally saturated.
01
What to look for
Darkened blue to black color can appear concentrated in porous zones and cracks. Surface may look unnaturally saturated.
02
What it means
Sugar-acid treatment darkens porous material by carbonizing sugar inside the structure. It is deceptive if sold as natural color.
03
Expert move
Compare color in cracks, pores, and broken edges. Suspiciously dark porous turquoise should be tested further.