---
title: "Slightly Included (SI1, SI2): meaning in gemology"
description: "SI1 and SI2 are the clarity grades for inclusions that are noticeable at 10x magnification."
url: https://digitalgemology.com/learn/glossary/si
image: https://digitalgemology.com/img/og-digital-gemology.png?v=d224fb01
---

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[Glossary](https://digitalgemology.com/learn/glossary) · Four Cs

# Slightly Included (SI1, SI2)

Also called SI, SI1, SI2

SI1 and SI2 are the clarity grades for inclusions that are noticeable at 10x magnification.

## In more detail

SI inclusions are easy to find at 10x, and sometimes you can see them by eye. Many SI stones still look clean at arm's length, so SI is a popular range. SI2 is the last grade before the included range.

## On a grading report

Written SI1 or SI2 in the clarity grade line.

## Related terms

- [Very Slightly Included (VS1, VS2)](https://digitalgemology.com/learn/glossary/vs): VS1 and VS2 are the clarity grades for small inclusions that a grader finds with some effort at 10x magnification.
- [Included (I1, I2, I3)](https://digitalgemology.com/learn/glossary/included): I1, I2 and I3 are the lowest clarity grades. Their inclusions are obvious at 10x and can affect transparency and brilliance.
- [Clarity grade](https://digitalgemology.com/learn/glossary/clarity-grade): The clarity grade says how free a diamond is of inclusions (inside) and blemishes (on the surface) at 10x magnification. GIA's scale has 11 grades in six categories, from Flawless (FL) to Included (I3).
- [Clarity plot](https://digitalgemology.com/learn/glossary/clarity-plot): The clarity plot is the map on a full grading report: an outline of the stone with symbols on it. Each symbol shows the type, position and approximate size of a clarity characteristic.

## Learn more

- [The diamond clarity scale explained, from FL to I3](https://digitalgemology.com/learn/four-cs/diamond-clarity-scale)
- [The clarity plot: how to read the inclusion map on a report](https://digitalgemology.com/learn/grading-reports/diamond-clarity-plot)

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