When you shop for moissanite, you will see color grades like "DEF" or "GHI" listed in product descriptions. This guide explains what these grades mean in plain language — without the jargon.
The Short Answer
DEF means the moissanite stone is colorless — it appears clear white, with no visible tint. GHI means the stone is near-colorless — it appears white in most lighting, with a very faint warm tint that may be visible under close inspection or in certain lighting conditions.
How Moissanite Color Grading Works
Moissanite uses the same letter-based color scale originally developed for diamonds. The scale runs from D (completely colorless) to Z (strongly yellow or brown tinted). For practical purchasing purposes, the relevant grades are:
| Grade Range | Description | Appearance |
|---|---|---|
| D, E, F | Colorless | Pure white, no detectable tint to the naked eye |
| G, H, I | Near-colorless | White appearance; very faint warmth visible under magnification or in certain lighting |
| J, K and below | Faint to light tint | Noticeable warm or yellowish tint, especially in face-up view |
Moissanite is graded in ranges (DEF together, GHI together) rather than individually, because the differences within each range are imperceptible to the naked eye and the grading instruments cannot reliably distinguish between, say, D and E in silicon carbide.
What DEF Looks Like in Real Life
A DEF moissanite appears completely white — indistinguishable from a colorless diamond to the naked eye. When set in white gold or platinum, the stone shows no warmth whatsoever. When set in yellow or rose gold, the warm metal reflects slightly into the stone, which can give any colorless stone a subtle warmth regardless of its grade — this is a metal reflection effect, not a stone color issue.
What GHI Looks Like in Real Life
A GHI moissanite appears white in most everyday lighting conditions. The faint warmth of GHI is most visible when the stone is placed face-down on a white surface or viewed under strong daylight alongside a DEF stone. On a finger, in a setting, under normal lighting, GHI appears white to the vast majority of viewers. GHI stones are priced lower than DEF and represent good value for buyers who prioritise size over absolute colorlessness.
Which Should You Choose?
For white gold or platinum settings, DEF is the recommended choice — the cool metal makes any faint warmth in a GHI stone slightly more visible. For yellow gold or rose gold settings, GHI is a perfectly reasonable choice — the warm metal absorbs and flatters a slight warmth in the stone, and the cost saving allows you to choose a larger stone.
All Moissanite Shine stones are DEF grade — colorless — as a standard. You do not need to choose between grades; DEF is what we carry.
Related reading:
Moissanite Color Grading: How DEF and GHI Are Measured
VVS1 vs VS1 Moissanite: What the Clarity Difference Actually Looks Like
How to Read a GRA Certificate