Recent discoveries over the last decade of new gemfields, exploitation of new and existing
deposits, and application of relatively new techniques have greatly increased our …

Megacrystic sapphires are frequently associated with alkaline basalts, most notably in Asia
and Australia, although basalt is not generally normative in corundum. Most of these …

Mineral inclusions and coexisting minerals of gem corundum from the Thailand area
analysed by SEM-EDS in this study can be divided into sapphire and ruby suites. The …

The 3309, 3232, and 3185 cm–1 are a series of peaks defined as the 3309 cm–1-series
peaks of the functional group absorptions in the mid-infrared region of gem corundum …

The blue color of blue sapphire is caused by the Fe-Ti pairs. Recently, the oxidation states of
Fe and Ti on high-quality blue sapphire were found as mixed acceptor states of Fe 3+ and Ti …

The proliferation of gemmological laboratory reports and the need for transparency to best
protect against litigation suggest that some gem-testing laboratories should consider …

Here, we present well-oriented hematite exsolutions in corundum megacrysts from Cenozoic
basalt in China. Crystallographic orientation relationships (CORs) and the interface …

Materials and methods The semitranslucent-opaque sapphire samples (again, Figure 1)
were obtained from Bang Ka Cha deposit in Chanthaburi. Their representative sample …

A large (112.64 ct) black star sapphire of probable Sri Lankan origin that exhibits 12-rayed
asterism was studied for this report. As in other 12-rayed star sapphires, its phenomenal …

Драгоценные камни с давних пор привлекают внимание людей своей красотой и
уникальностью. Но много ли мы знаем о том, где они рождаются и растут в природе …