- Education
- Diamond Anatomy & Light
Diamond Anatomy & Light
Anatomy of a diamond: table, crown, girdle, pavilion and culet explained
Every cut diamond is built from the same handful of parts. Once you know what they are and how they work together, grading reports and sparkle start to make far more sense.
A polished diamond has five main zones. The table is the large flat facet on top. The crown is the angled upper section. The girdle is the thin outer edge. The pavilion is the lower cone, and the culet is the point or tiny facet at the base. Their sizes and angles decide how light enters the stone, bounces inside it and returns to your eye.
These guides start with the parts themselves, such as table and depth and crown and pavilion angles. They then explain how those measurements create brilliance, fire and contrast. From there you can learn to spot common cut faults like windowing and the bow tie, and see why two diamonds of the same carat weight can face up at different sizes.
Later guides cover the round-diamond proportion styles that enthusiasts debate, how to read ASET and Idealscope images, and proportion charts for fancy shapes. They're written by the GemTrove team, which has been in the trade since 2008 and is led by Graduate Gemologist (GIA) Raj Sood.
Start here
A simple path through the basics
- Diamond Table and Depth ExplainedBegin with the two percentages on every grading report and what they say about a diamond's shape.
- Diamond Crown & Pavilion Angles ExplainedSee how the angles above and below the girdle steer light back to your eye.
- Diamond Girdle Thickness ExplainedUnderstand the diamond's edge, why its thickness matters for durability and how it affects apparent size.
- What Is a Diamond Culet?Learn what the culet is, what 'none' means on a report and when a visible culet becomes a problem.
- Diamond Fire, Brilliance & Scintillation ExplainedBring the parts together and learn the three kinds of sparkle that good proportions produce.
Diamond Anatomy & Light
The parts of a diamond
Diamond Anatomy & Light
How a diamond handles light
Diamond Anatomy & Light
Size, spread and outline
Diamond Anatomy & Light
Common cut faults
Diamond Anatomy & Light
Round diamond proportion styles
Diamond Anatomy & Light
Reading light performance images
Diamond Anatomy & Light
Proportion charts for fancy shapes
Diamond Anatomy & LightIdeal Proportions Chart: Cushion Diamonds
Diamond Anatomy & LightIdeal Proportions Chart: Emerald Cut Diamonds
Diamond Anatomy & LightIdeal Proportions Chart: Pear Diamonds
Diamond Anatomy & LightIdeal Proportions Chart: Radiant DiamondsEvery guide
All 30 diamond anatomy & light guides
Show all 30 guides
- Diamond Table and Depth Explained
- Diamond Crown & Pavilion Angles Explained
- Diamond Girdle Thickness Explained
- What Is a Diamond Culet?
- Round Diamond Proportions Beyond the Cut Grade
- Diamond Fire, Brilliance & Scintillation Explained
- Diamond Light Performance Guide
- What Is Light Leakage in a Diamond?
- Extinction and Dark Zones in Diamonds
- Diamond Symmetry vs Optical Symmetry
- Diamond Transparency & Haziness Explained
- Why Same-Carat Diamonds Can Look Different
- Diamond Spread and Face Up Size Guide
- Diamond Length to Width Ratio Guide
- Diamond Bow Tie Effect
- Windowing Across Diamond Shapes
- Fisheye Effect in Diamonds
- Nailhead Effect in Diamonds
- Hearts and Arrows Diamonds: What Are You Actually Paying For?
- Shallow Round Diamonds: Bigger Spread, Better Value?
- Steep-Deep Round Diamonds Explained
- 60/60 Round Diamonds vs Classic Proportions
- Painting and Digging Out in Round Diamonds
- ASET and Idealscope Images Explained
- Hearts and Arrows Viewer Explained
- Ideal Proportions Chart: Oval Diamonds
- Ideal Proportions Chart: Cushion Diamonds
- Ideal Proportions Chart: Emerald Cut Diamonds
- Ideal Proportions Chart: Pear Diamonds
- Ideal Proportions Chart: Radiant Diamonds
Ask a gemologist
Talk it through with a gemologist
Raj Sood is a Graduate Gemologist (GIA) and master jeweller. Bring the stones you are considering, or send the reports, and he will explain the differences in plain language.
FAQ
Diamond Anatomy & Light questions
What are the main parts of a diamond?
A cut diamond has a table (the top flat facet), a crown (the upper angled section), a girdle (the outer edge), a pavilion (the lower cone) and a culet (the base point or small facet). Together, their proportions determine how the stone handles light.
Which part of a diamond matters most for sparkle?
No single part works alone, but the pavilion angle has the biggest influence on brightness because it controls whether light reflects back up or leaks out the bottom. The crown angle and table size then shape how much fire and contrast you see.
Why do two diamonds of the same carat weight look different in size?
Carat is weight, not size. A diamond that carries extra weight in a deep pavilion or thick girdle will have a smaller face-up diameter than a well-proportioned stone of the same weight.
Is a thick girdle a bad thing?
A medium to slightly thick girdle helps protect the edge from chipping. A very thick girdle adds hidden weight and makes the diamond look smaller for its carat, while a very thin girdle is more vulnerable to damage.
Should a diamond have a culet?
Most modern diamonds have no culet or a very small one, which is invisible face up. A large culet can show as a dark or see-through dot in the centre, so 'none' to 'small' is generally preferred.
Do fancy shapes have ideal proportions like round diamonds?
Fancy shapes don't have one agreed ideal standard the way rounds do, so grading labs rarely give them a cut grade. Proportion ranges for table, depth and length-to-width ratio are still a useful guide, though judging the actual stone's appearance matters most.