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Há 4 dias · The gemstone refractive index, commonly abbreviated as RI, measures the difference between the speed of light in air and the speed of light in a stone. For example, the refractive index of a diamond is 2.417 – 2.419, which means that the speed of light in a diamond is 2.42 times slower than in air. Every gemstone has a unique refractive index ...
Há 4 dias · Stuller Gemstones™ Sourced from all corners of the world, Stuller Gemstones stand out for their quality and brilliance. Stuller is committed to ethical sourcing, fair-trade practices, and the highest degree of transparency. We work with trusted sources who have an established record of environmental and social integrity.
26 de jan. de 2018 · Tuzlukov showed us on the rough tsavorite where he envisioned the table, the crown, and the pavilion. He said sometimes he knows immediately upon looking at a rough stone what the cut stone will look like (figure 5). Other times he thinks about it “for months or longer.” His approach to cutting gemstones is undeniably metaphysical.
6 de mai. de 2024 · It has a Mohs hardness of 7 and a glassy shine when polished. Most citrine gemstones are transparent or translucent. Colors: Citrine is usually predominantly yellow, with variations including pale yellow, golden yellow, and yellowish orange. Dark orange-red gem material, known as madeira citrine, is the most valuable. Rarity: Natural citrine is ...
Há 2 dias · Topaz is allochromatic, which means that its color is caused by impurity elements or defects in its crystal structure rather than by an element of its basic chemical composition. The element chromium causes natural pink, red, and violet-to-purple colors in topaz. Imperfections at the atomic level in topaz crystal structure can cause yellow ...
10 de mai. de 2024 · Established in 1931, the Gemological Institute of America (GIA) is the world’s foremost authority on diamonds, colored stones, and pearls. A public benefit, nonprofit institute, GIA is the leading source of knowledge, standards, and education in gems and jewelry. Welcome to GIA. Students around ...
Há 20 horas · Youm-e-Takbeer is celebrated as a national day in Pakistan on May 28 in commemoration of Chagai-I and Chagai-II series of nuclear tests. The nuclear tests made…
