The Carat Standard

IGI report LG782687184

2.51 ct Emerald Laboratory-Grown Diamond

88/100 · Refined

A strong candidate on paper; confirm its light pattern in imagery.

What reads well

  • A 1.38:1 length-to-width ratio sits in the classic emerald cut range.
  • Face-up spread (8.83 × 6.40 mm) is typical or better for a 2.51 ct emerald cut.
  • Excellent polish and symmetry, the top finish grades.
  • E color is in the colorless range.
  • VS1 clarity is typically eye-clean in an emerald cut.

What deserves a closer look

  • A 70.3% depth is deep for a step cut: weight sits below the girdle and the stone faces up smaller.
  • Screening only: for this emerald cut, check images or video of the exact stone for the "hall of mirrors" step pattern, any see-through window under the table and clean corners.
  • Treatment status is not stated on the report. For a laboratory-grown diamond, ask whether it is as-grown or post-growth treated.

The reading, field by field

Table · Ideal
At 68%, the table sits within the typical 60–69% range for an emerald cut, balancing brightness with fire.
Total depth · Closer look
70.3% is deeper than typical for an emerald cut (60–69%). Extra depth holds weight below the girdle, so the stone can face up smaller than its carat weight suggests.
Length-to-width · Ideal
A 1.38:1 outline is within the classic 1.3–1.5:1 range for an emerald cut.
Polish · Ideal
Excellent polish is the top finish grade — facets are cleanly executed with nothing that would soften sparkle.
Symmetry · Ideal
Excellent symmetry is the top finish grade — facets are cleanly executed with nothing that would soften sparkle.
Girdle · Ideal
Slightly thick: a durable girdle thickness that doesn't hide meaningful weight.
Culet · Ideal
Long: a keel-line culet, normal for elongated step and modified cuts.
Color · Ideal
E is in the colorless range and faces up white in any metal.
Clarity · Favorable
VS1 is typically eye-clean, though step cuts show inclusions more readily — worth a close look at the images.
Fluorescence · Ideal
None: no meaningful effect on appearance.

What to check on the exact stone

  • With 70.3% depth, does this stone face up smaller than a typical 2.51 ct emerald?
  • With open step facets, is the center completely eye-clean without any visible dark marks?
  • Does this CVD diamond show any brown or gray undertone face-up in daylight?
  • Can you show me the inscribed report number under a loupe before it is set?

Report facts

Origin
Laboratory-grown
Carat
2.51 ct
Shape
Emerald
Cut grade
Not given for this shape
Color
E
Clarity
VS1
Measurements
8.83 × 6.40 × 4.50 mm
Table
68%
Total depth
70.3%
Crown angle
Not given for this shape
Pavilion angle
Not given for this shape
Polish
Excellent
Symmetry
Excellent
Girdle
Slightly thick
Culet
Long
Fluorescence
None

About The Carat Standard Score

How The Carat Standard reads a report