CDG Diamond Cutting & Polishing Standards 1 — Questions and Answers

Question 1: What is the main goal of diamond cutting?

To increase weight only.
To maximize brilliance and fire (Correct answer)
To change its color.
To reduce clarity.

Correct answer: To maximize brilliance and fire

The main goal of diamond cutting is to maximize the diamond's optical properties, specifically its brilliance (white light reflection), fire (dispersion of light into spectral colors), and scintillation (sparkle). An expertly cut diamond will reflect and refract light efficiently, creating a dazzling display. This process often involves sacrificing carat weight to achieve optimal beauty.

Question 2: What tool is commonly used to cut diamonds?

Laser cutters.
Diamond saws (Correct answer)
Water jets.
Electric knives.

Correct answer: Diamond saws

Due to diamond's extreme hardness, specialized tools are required for its cutting. Diamond saws, which are thin blades impregnated with diamond dust, are commonly used to precisely cut rough diamonds into smaller sections or to remove inclusions. Lasers are also employed for more intricate cuts, but diamond saws remain fundamental for initial shaping.

Question 3: What does polishing do to a diamond?

Changes the color.
Removes surface roughness (Correct answer)
Increases size.
Reduces clarity.

Correct answer: Removes surface roughness

Polishing is the final and crucial stage of diamond cutting, where the facets are meticulously smoothed to a high shine. This process removes any microscopic surface roughness or scratches left from the cutting and bruting stages. A perfectly polished surface is essential for maximizing a diamond's ability to reflect and refract light, thereby enhancing its brilliance and sparkle.

Question 4: What is 'symmetry' in diamond cutting?

Facet shape only.
Uniformity of facet arrangement (Correct answer)
Color consistency.
Weight distribution.

Correct answer: Uniformity of facet arrangement

Symmetry in diamond cutting refers to the precision and balance of a diamond's facet arrangement and overall shape. It evaluates how well the facets are aligned, proportioned, and meet at precise points, ensuring the diamond is perfectly round and its facets are evenly distributed. Excellent symmetry is critical for optimal light performance, allowing light to reflect and refract uniformly within the stone.

Question 5: Why is the pavilion angle important in cutting?

It affects clarity.
It controls light reflection (Correct answer)
It determines carat weight.
It changes color.

Correct answer: It controls light reflection

The pavilion angle, which is the angle formed by the pavilion facets and the girdle, is a critical factor in a diamond's cut quality. An optimal pavilion angle ensures that light entering the diamond is internally reflected back through the crown, maximizing its brilliance and fire. If the angle is too shallow or too steep, light will 'leak' out the bottom or sides, diminishing the diamond's sparkle.

Question 6: What is a common shape for polished diamonds?

Round brilliant (Correct answer)
Square cut.
Heart shape.
Oval cut.

Correct answer: Round brilliant

The round brilliant cut is the most popular and common shape for polished diamonds, accounting for the vast majority of diamonds sold. Its sophisticated facet arrangement, typically 57 or 58 facets, is specifically engineered to maximize a diamond's brilliance, fire, and scintillation. This makes it the benchmark for diamond beauty and optical performance.

Question 7: What is 'bruting' in diamond cutting?

Polishing facets.
Shaping the diamond round (Correct answer)
Cutting facets.
Color grading.

Correct answer: Shaping the diamond round

Bruting, also known as girdling, is the process of shaping a rough diamond into a preliminary round form. This is typically done by rubbing two diamonds together on a spinning lathe, which creates the rough outline of the girdle. It's a crucial initial step in preparing a diamond for the precise facet cutting that follows, especially for round brilliant cuts.

Question 8: What is the purpose of the girdle on a diamond?

Reflect light.
Protects diamond edges (Correct answer)
Change color.
Weight the diamond.

Correct answer: Protects diamond edges

The girdle is the narrow band around the widest part of a polished diamond, separating the crown (top) from the pavilion (bottom). Its primary purpose is to protect the diamond's delicate edges from chipping and damage during setting and everyday wear. A well-proportioned girdle also contributes to the diamond's overall durability and aesthetic balance.

Question 9: Why is polishing important after cutting?

It improves color.
It enhances sparkle (Correct answer)
It adds weight.
It changes shape.

Correct answer: It enhances sparkle

Polishing is essential after cutting because it creates smooth, highly reflective facet surfaces that are crucial for a diamond's optical performance. Rough or unpolished surfaces scatter light, significantly diminishing the diamond's brilliance and fire. A high-quality polish ensures that light enters and exits the diamond efficiently, maximizing its sparkle and overall visual appeal.

CDG Diamond Cutting & Polishing Standards 1

What is the main goal of diamond cutting?