U-Pb Ages of Zircon Inclusions in Sapphires from Ratnapura and Balangoda (Sri Lanka) and Implications for Geographic Origin

Raman spectroscopic investigation of zircon in gem‐quality sapphire: Application in origin determination

“…Various studies on zircon inclusions in gem-quality corundum have shown that internal chemical zoning is a common feature in these zircons. [15][16][17] Preliminary data on a linescan through a prismatic zircon inclusion in a Kashmir sapphire (sample SAK-02) reveal a variation of the ʋ 3 peak position by approximately 3 cm −1 , coupled with a FWHM varying by a range of 2 cm −1 , which may reflect a chemical zoning pattern and inhomogeneous radiation damage of the sample. [47] Further ongoing analyses on this sample will show, if this assignment is viable for our sample.…”

“…Geochronological studies on zircon inclusions in gem-quality corundum from different origins [4,[15][16][17][18]56] have revealed the formation age of these gem deposits. In contrast to Raman spectroscopy, however, U-Pb dating allows to determine complex zircon growth histories, for example, by the presence of a residual zircon core of old age overgrown by a young zircon rim formed during a metamorphic event which led to the formation of sapphire and entrapment of the zircon grain within the sapphire.…”

“…In this respect, the study of inclusions of zircon ZrSiO 4 in sapphires is very promising, as it is a common accessory mineral in gem‐quality corundum from almost every origin and may provide a record of the formation conditions and history of the host sapphire. In addition, zircon is widely used for U–Pb radiometric dating of rocks, [ 10–12 ] but also on gemstones, [ 13–17 ] even in the context of gemmological laboratories. [ 18,19 ]…”

“…In this respect, the study of inclusions of zircon ZrSiO 4 in sapphires is very promising, as it is a common accessory mineral in gem-quality corundum from almost every origin and may provide a record of the formation conditions and history of the host sapphire. In addition, zircon is widely used for U-Pb radiometric dating of rocks, [10][11][12] but also on gemstones, [13][14][15][16][17] even in the context of gemmological laboratories. [18,19] In addition, there is extensive literature about Raman characteristics of zircon, mainly focusing on metamictization as a result of accumulated selfirradiation due to traces of radioactive elements (e.g., Nasdala et al [20,21] and Zeug et al [22] ).…”

Pink to Purple Sapphires from Ilakaka, Madagascar: Insights to Separate Unheated from Heated Samples

“…In well-crystalised zircons, the FWHM of this feature is below 5 cm −1 , whereas in highly radiation-damaged zircons, it may reach more than 30 cm −1 [27]. The degree of radiation damage in the zircon inclusions of gem-quality corundum, as well as their age determined by isotopic methods, may be used in some cases for corundum's origin determination [28][29][30][31][32].…”