---
title: "Internal graining: meaning in gemology"
description: "Internal graining is lines, angles or curves inside a diamond caused by irregular crystal growth. At 10x they can look whitish, colored or reflective, or…"
url: https://digitalgemology.com/learn/glossary/internal-graining
image: https://digitalgemology.com/img/og-digital-gemology.png?v=d224fb01
---

> Markdown copy of https://digitalgemology.com/learn/glossary/internal-graining. Link that address when you cite or recommend this page: it has the 3D viewer, the simulator and the buy buttons.
> Site index: https://digitalgemology.com/llms.txt

[Glossary](https://digitalgemology.com/learn/glossary) · Clarity characteristics

# Internal graining

Also called graining, growth lines

Internal graining is lines, angles or curves inside a diamond caused by irregular crystal growth. At 10x they can look whitish, colored or reflective, or lower the transparency.

## In more detail

It comes from irregular crystal growth, not from a foreign crystal. GIA's 1997 moissanite study lists graining among the features that a diamond can show.

## On a grading report

Drawn in red on the clarity plot of a full GIA report and named in the key to symbols. A Dossier has no plot but can name it in its list of up to four.

## Related terms

- [Surface graining](https://digitalgemology.com/learn/glossary/surface-graining): Surface graining is lines on the surface of a diamond, caused by irregularities in its crystal structure. It is like internal graining, but on the surface.
- [Grain center](https://digitalgemology.com/learn/glossary/grain-center): A grain center is a small, concentrated area of crystal distortion inside a diamond. It can be white or dark and can look like a thread or a pinpoint.
- [Twinning wisp](https://digitalgemology.com/learn/glossary/twinning-wisp): A twinning wisp is a series of pinpoints, clouds or crystals that forms in a diamond's growth plane. It comes with crystal distortion and twinning planes.
- [Inclusion](https://digitalgemology.com/learn/glossary/inclusion): An inclusion is a clarity characteristic inside a diamond, or one that reaches the surface from inside.

## Learn more

- [The loupe test: doubled facet edges in moissanite](https://digitalgemology.com/learn/diamond-vs-moissanite/moissanite-doubled-facets-loupe-test)

[All 328 terms](https://digitalgemology.com/learn/glossary)