Diamond Grading & Classification Flashcards

A 'bearded girdle' on a diamond refers to:

Answer: Tiny feathers extending inward from the girdle edge

A bearded girdle has tiny feathers or fractures extending from the girdle surface into the stone, typically caused by excessive bruting pressure.

Which of the 4Cs has the greatest impact on a diamond's price per carat for two otherwise identical stones?

Answer: Carat weight

Larger diamonds are far rarer per carat than smaller ones, so carat weight causes exponential price increases per carat for otherwise equivalent stones.

What type of inclusion is described as a long, thin, needle-like crystal inside a diamond?

Answer: Needle

A needle is a long, thin included crystal that looks like a tiny rod or needle under magnification.

In the GIA grading system, the grade 'Internally Flawless (IF)' means:

Answer: No inclusions visible under 10x but minor blemishes allowed

An IF grade permits minor surface blemishes but requires no internal inclusions to be visible under 10x magnification.

When comparing two diamonds of equal cut, color, and clarity, a 1.00 ct stone will typically cost more per carat than a 0.90 ct stone primarily because:

Answer: Magic sizes carry a market premium

Round-number 'magic sizes' like 0.50, 0.75, 1.00, and 2.00 carats command a price premium due to consumer demand at these milestones.

What is the purpose of a diamond grading report's 'key to symbols' section?

Answer: Identifies each type of inclusion mapped on the plotting diagram

The key to symbols decodes the plotting symbols on the clarity diagram, identifying what type of inclusion or blemish each symbol represents.

A diamond described as 'eye clean' means:

Answer: No inclusions visible without magnification to the unaided eye

Eye clean is an industry term meaning no inclusions are visible when examined without magnification under normal viewing conditions.