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ACA Gemological Laboratory.

Identify the Ideal by the Eye of the Diamond

Here is a surefire way to recognize Ideal cut diamonds at a glance. Learn to look for the “eye of ...
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The Overgrading of Blue-Fluorescent Diamonds

Michael D. Cowing FGA AGA Certified Gem Laboratory email: Abstract: Decades after the establishment in the mid-twentieth century of ultraviolet-free ...
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Over Grading of Blue Fluorescent Diamonds Revisited

Nineteen years ago GIA published the results of a human experiment in the observation of diamonds with various amounts of ...
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ACA Gemological Laboratory.

A Place for CZ Masters in Diamond Colour Grading

Figure 2. Complete set of GIA graded diamond masters from E through M. Over the last 20 years and despite ...
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