Introduction of modern technologies and methods and quality analysis for the gemstone
industry are the main strategic initiatives of the Small and Medium Development Authority …

Over recent decades, numerous studies have highlighted the importance of opal,
chalcedony and quartz varieties, chiefly in volcanic, but also in metamorphic and …

This study assesses the efficiency of ultrasonic treatment on oil sludge, with a specific focus
on the impact of particle size and content, crude oil viscosity, and the interactions between …

The effect of heat treatment on amethyst color was studied from a new perspective of
chromaticity of gemstones and the cause of amethyst coloration was discussed based on the …

In the present paper, we have performed the Fourier transform infrared (FTIR) and
thermoluminescence (TL) characterizations of gamma-irradiated (dose 0.5–50 kGy) …

In this paper, we present the results of research on the thermoluminescence (TL) and optical
absorption (OA) properties of colorless natural quartz (including natural quartz samples …

The shielding features of amethyst, chalcedony, crystal rock, milky, pink, flint, and jasper
quartz were calculated. The seven varieties of quartz were collected within the territory of the …

In order to study the effect of impurity iron in different valence states on the coloration
mechanism of quartz, colorless synthetic quartz fabricated via ion implantation and its …

This study explored the thermoluminescence (TL) properties of various quartz types
(amethyst, citrine, rock crystal, and rose quartz) when exposed to gamma irradiation …

Mössbauer spectroscopy of green (prasiolite) and violet (amethyst) quartz crystals from the
Sudety Mountains (Poland) has shown that neither Fe 2+ nor Fe 4+ ions are present in them …