这一组原石和成品蓝宝石显示了蓝色至紫罗兰色或紫色色彩的广泛范围，以及可以在约戈蓝宝石中发现的由淡到深的色度组合。最大的刻面宝石是一颗 1.44 克拉的垫型切工宝石。由 Bill Vance（比尔·万斯）友情提供。摄影：Kevin Schumacher（凯文·舒马赫） 尽管美国 ...

We grade only loose diamonds because a mounting or setting can obscure or influence the color and clarity grade and make it difficult to determine an exact carat weight. Grading loose stones also ...

GIA has studied more than 400 important gemstones in the Edward J. Gübelin Gem Collection and is committed to sharing this repository of gemological information. Dr. Edward Gübelin’s lifelong study of ...

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 ...

Zircon comes in a wide variety of colors. Colorless zircon is well known for its brilliance and flashes of multicolored light, called fire. These two zircon properties are close enough to the ...

Adjacent amethyst and citrine colors in the same crystal of quartz have been reported from South America, although there appears to be uncertainty as to the exact locality of origin. Such material has ...

橄榄石、尖晶石和褐红条纹玛瑙是三种八月生日石。众所周知，橄榄石生日石是在极端条件下形成的，可在硬化的熔岩中找到。这些岩浆从地幔深处携带橄榄石而来，也可以从来自外太空的陨石中发现橄榄石。尖晶石生日石直到最近才受到人们重视，因为如今 ...

Diamond is available in a range of sizes and qualities to fit every consumer's tastes. One of the first things most people learn about diamonds is that not all diamonds are created equal. In fact, ...

这颗大型澳大利亚淡色凸圆面蛋白石，重达 117.85 克拉。蛋白石上面布满了橙色和绿色的星火图案小型游彩闪光，灰色的体色缀以柔和的蓝色斑点。 每一颗蛋白石的外观和质量都大有不同。正如雪花和指纹一样，每颗宝石都有明显的差异。 蛋白石评估应在可控 ...

オズの魔法使いの50周年を記念して、ハリー·ウィンストンは4600のルビーが設置された本物のルビーのスリッパを作成しました。 - Harry Winston(ハリー・ウィンストン)提供 赤は、私達の最も強い感情、つまり愛と怒り、情熱と憤慨の色です。 それは速い車や ...

This amethyst crystal is from Namibia. It shows classic quartz crystal shape: a six-sided columnar crystal with a pyramid-shaped termination at the top. Courtesy Daniel Trinchillo, Fine Minerals ...

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" ...