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LUMORA

Certification

Check a report number

Every stone we sell is graded by an independent laboratory and ships with its report number. Enter it below to see the stone in our inventory, or go straight to the laboratory to verify the certificate itself.

Understanding the grade

The four Cs

Carat

Weight, not size — one carat is 0.2 grams. Two stones of equal carat can look different sizes depending on how the weight is distributed, which is why cut matters as much as carat when you are choosing for appearance.

Colour

Graded D to Z, where D is colourless. The scale measures absence of colour, not presence. Most buyers cannot see the difference between adjacent grades once a stone is set.

  • D
  • E
  • F
  • G
  • H
  • I
  • J
  • K

Clarity

How free the stone is of internal inclusions, assessed at 10× magnification. Anything VS2 or better is normally clean to the naked eye.

FL
Flawless — no inclusions visible at 10× magnification
IF
Internally flawless — surface blemishes only
VVS1
Very very slightly included — inclusions extremely difficult to see at 10×
VVS2
Very very slightly included — very difficult to see at 10×
VS1
Very slightly included — difficult to see at 10×
VS2
Very slightly included — somewhat easy to see at 10×
SI1
Slightly included — noticeable at 10×, usually clean to the eye
SI2
Slightly included — easily seen at 10×, may be visible to the eye

Cut

How well the stone returns light — the one C that is about workmanship rather than the raw material. It has more effect on how a diamond looks than any other grade, and it is where twenty years of cutting experience shows.

  • Ideal
  • Excellent
  • Very Good
  • Good

Common questions

Are laboratory-grown diamonds real diamonds?
Yes. They are chemically, physically and optically identical to mined diamonds — the same crystal, the same hardness, the same refraction. The difference is origin, not substance. Standard gemmological testing cannot separate them by appearance; laboratories identify them by growth features, which is why every stone is graded and inscribed.
What is the laser inscription?
A microscopic code laser-etched onto the girdle — the thin outer edge of the stone. It carries the report number and, on laboratory-grown stones, a statement of origin. It is invisible to the naked eye and does not affect the grade. It is how you confirm a specific stone matches a specific certificate.
Which laboratories do you use?
IGI and GIA. Both grade laboratory-grown diamonds against published, consistent standards, and both let anyone verify a report number on their own website without going through the seller.
The photograph and the certificate disagree. Which is right?
The certificate. Photographs are affected by lighting and screen calibration; the grading report is a measured assessment. Where they differ, the report governs — that is stated in our terms.

Still unsure about a stone?