Kunzite is one of the most famous varieties of spodumene, and it is known for light pink to violetish purple. Kunzite was named after pioneering gemologist George Frederick Kunz, who was the first one to identify a pink stone from California as a variety of spodumene in 1902. Kunzite was found in Brazil, Afghanistan, Madagascar, and Nigeria (Mauthner, 2011).

Color zoning refers to the uneven distribution of color within a gemstone, which is mainly caused by temperature changes or the uneven incorporation of certain trace elements during the gem’s formation (Gilbertson, 2016). Blue sapphires usually develop significant color zoning.

Pargasite is a calcareous amphibole with the chemical formula NaCa2(Mg4 Al)(Si6 Al2)O22(OH)2, which can appear in different shades of green depending on the Fe content. Pargasite usually occurs in corundum as prisms, needles, and platelets.

Natural emerald with inclusions along three directions.

Emeralds with highly saturated green color and pure clarity are strongly cherished and coveted by gem dealers and collectors. Those green beauties with the socalled“Gota de aceite”optical phenomenon are rarer. Rarity of such samples causes the scarcity of related research on this subject. This article reports on thegemological features of one 5.1ct emeraldwith distinct“gota de aceite”effect.Also, the possible cause of“gota de aceite”is described and illustrated in crystalline structural perspective.