Laser sawing of diamonds is beginning to revolutionize the diamond-cutting industry. Not only does the laser saw offer savings in time and money, but it also enables the cutting of material virtually ...

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Pietersite has been described as a brecciated variety of tiger’s-eye. This study examined pietersite specimens from Namibia and China (the main sources) using powder X-ray diffraction, optical ...

Figure 1. Faceted manufactured glass beads measuring approximately 8 mm in diameter. Photo by Robison McMurtry. A collection of lovely faceted blue beads was presented to author EAS during an annual ...

Over the last two decades, knowledge of the formation of gem deposits has improved significantly. This article reviews the state of our knowledge of the geology and genesis of gem corundum and emerald ...

Bluish green tourmaline crystals and white calcite on a Burmese ruby. Photo by Charuwan Khowpong; field of view 2.48 mm. During a GIA field expedition to Mogok, Myanmar, a tiny but interesting sample ...

This ancient necklace dates to 2000BCE. An inscription on the center stone is a South Arabian script from the 8th century BCE. - From "Gems and Gemstones: Timeless Natural Beauty of the Mineral World" ...

这颗晶体显示出供其生长的母岩的痕迹。 优质丹泉石有很强的多向色，且正面呈现鲜艳的紫到蓝色，这两种特点有助于鉴定宝石，也对宝石的价值有很大的影响。颜色较暗淡的宝石更为常见 ...

However gem quality diamonds are fashioned from the original crystal shape they possess a combination of brightness, sparkle, fire, and sense of purity not matched by other gems. - Jeff Scovil, ...

GIA evaluates lapis lazuli but does not grade it. A GIA Colored Stone Identification Report assesses the characteristics of any polished, rough, mounted or loose material (weight, measurements, shape, ...

Most colored gemstones form near the earth’s surface in a wide range of different environments; for example, they can crystallize from igneous magmas or hydrothermal solutions, or via the ...

This 7.19-carat alexandrite was cut to feature its beautiful color change. When the light source changes from daylight to incandescent light, the gem’s color changes from bluish green to reddish ...