Lab Grown Diamond Culet: What It Is and How It Affects Appearance

The culet — pronounced "KYOO-let" — is the tiny point (or facet) at the very bottom of a diamond. While it's the smallest detail on any diamond, the culet can have a surprisingly visible impact on how your stone looks when viewed from above.

What Exactly Is the Culet?

The culet is where the pavilion facets converge at the bottom of the diamond. It can be:

• A sharp point — all pavilion facets meet at a single point (described as "None" or "Pointed" on the certificate)
• A small flat facet — the point is cut off, creating a tiny additional facet (described by size: Very Small, Small, Medium, etc.)

Culet Size Grades

Grade	Description	Recommendation
None / Pointed	No culet facet — perfect point	IDEAL — most common and desirable today
Very Small	Tiny facet, invisible without magnification	Excellent — no visible impact
Small	Small facet, barely visible under 10x	Good — acceptable in most settings
Medium	Noticeable facet under 10x	Acceptable — may show slight dark spot face-up in larger stones
Slightly Large	Visible under 10x, may be visible to naked eye	Not ideal — visible dark spot possible
Large	Clearly visible even to the naked eye	Avoid — obvious dark spot visible through the table
Very Large / Extremely Large	Prominently visible	Avoid completely

How the Culet Affects Appearance

The Dark Spot Effect

When a culet is large enough to be visible, it appears as a dark spot or circle when you look into the diamond from above (through the table). This happens because:

• Light that enters the diamond and reaches the culet facet exits through the bottom instead of reflecting back up
• The flat culet facet creates a "window" that lets light escape, appearing dark against the surrounding brilliance
• The larger the culet, the more prominent this dark spot becomes

Light Performance Impact

A pointed culet (None) is ideal because all pavilion facets converge to a single point, maximizing the amount of light that bounces back through the crown. Even a small culet facet represents a tiny area where light escapes rather than reflects.

However, for Very Small and Small culets, the impact on total light return is negligible — we're talking about fractions of a percentage of total light performance.

Historical Context

Interestingly, large culets were common in antique diamonds. Older cutting techniques deliberately created sizeable culet facets to:

• Prevent the delicate point from chipping (diamond cutting tools were less precise)
• Allow light to exit the bottom (antique diamonds were often viewed by candlelight where bottom-exit light created a unique glow)

Modern cutting technology produces pointed culets with minimal chipping risk, which is why "None" is now the standard for quality lab grown diamonds. If you're interested in the antique aesthetic, vintage-inspired designs sometimes intentionally incorporate small culets as a period detail.

Lab Grown Diamonds and Culets

Lab grown diamonds benefit from controlled growth processes that produce crystals with predictable properties. Modern cutting of lab grown stones almost universally produces pointed culets (None grade) because:

• Precision cutting technology handles the delicate point without chipping risk
• Consistent crystal quality means fewer structural weaknesses at the point
• Market preference for maximum light performance drives pointed culet standards

Culet and Diamond Shape

Different diamond shapes handle culets differently:

Round Brilliant

The round brilliant's symmetrical pavilion makes the culet position critical. Any culet facet is centered directly under the table, making it maximally visible. None/Pointed is strongly recommended.

Princess Cut

The princess cut's keel-style bottom (ridge instead of point) means the traditional culet concept doesn't apply the same way.

Emerald and Asscher

These step cuts have open tables that act as large windows into the stone. Any culet is more visible in step cuts than in brilliant cuts. None/Pointed is particularly important here.

Oval, Pear, Marquise

These elongated shapes have the culet positioned along the central axis. The culet is typically pointed and, if present as a small facet, is less visible than in rounds due to the elongated brilliance pattern.

What to Look For When Buying

On Your Certificate

Your diamond certificate lists culet size in the proportions section, usually as one of these grades. For quality lab grown diamonds, you'll typically see "None" or "Very Small."

Practical Priorities

1. Ideal: None / Pointed — the standard for quality modern diamonds
2. Acceptable: Very Small to Small — invisible to the naked eye, no practical impact
3. Caution: Medium — may show a small dark spot in larger diamonds (1.5ct+)
4. Avoid: Anything Slightly Large or larger — visible dark spot

Relative Importance

In the hierarchy of diamond quality factors, culet ranks below cut grade, symmetry and polish, and depth and table proportions. If all other factors are Excellent, a Very Small culet will never be noticed or regretted.

Recommended Pieces

• 14K White Gold 2 1/2Ct Round/Marquise/Yellow Pear Ladies
• Eternal Blush Collection 14K White Gold 2.00Ct Pink Pear/Pear
• 14K White Gold Crafted with 18K Yellow Gold Back Plate 1 1/4Ct

Every diamond in our collection features optimal culet proportions — selected to ensure maximum brilliance from every angle.