SI Clarity Diamonds

Diamond grading helps standardize and set the value and price of all diamonds. Labs use trained staff known as gemologists and special equipment to accurately identify the characteristics and attributes of every diamond. A diamond’s sparkle is represented by its graded components such as clarity.

Clarity is graded face up under 10x magnification with a tool called a loupe or diamond microscope. This is used to identify the tiny imperfections known as clarity inclusions. When these inclusions, given their type, size, number and location, are noticeable, that are graded as SI or slightly included. SI falls in the center of the clarity scale.

What is an SI Diamond

SI means the diamond has small inclusions that are noticeable with 10x magnification and may possibly be seen without any magnification, especially if they are larger or in the center of the diamond where facets aren’t helping to hide the inclusions. SI has a range that consists of SI1 and SI2 (slightly included 1 and slightly included 2). SI1 means smaller inclusions in number, size and location than SI2. The size of the inclusions tends to be medium in nature and the location can be anywhere (center under the table or on the sides near the diamond girdle). SI diamonds tend to have more centered inclusions because they are noticeable. The number of SI2 and SI1 inclusions can vary. It can be a single inclusion or several at a time. Typically, you can expect that there will be 1 grade setting inclusion rather than many smaller ones.

Common SI1 inclusions are crystal (white or black), feather, indented natural, knot, needle, cavity, chip, clouds, twinning wisps. Common SI2 inclusions are crystal (white or black), feather, indented natural, knot, needle and cloud, cavity, chip, twinning wisps as well. Because SI diamonds are below VS2 (very, slightly included 2), they are for the more budget conscious purchaser and offer a very good value. Less than 50% of all of the world’s gem quality diamonds are in this range. SI diamonds can be 10% - 20% less expensive than a VS diamond. They are very much in demand, especially SI1, because the inclusions aren’t outwardly obvious. They allow consumers to have other C’s such as carat or color optimized. The clarity grading scale is below with real images of SI stones.

10x zoom magnified diamond example, typical for diamond clarity grading
10x zoom
10x zoom with I1 clarity inclusions
10x zoom with SI2 clarity inclusions
10x zoom with SI1 clarity inclusions
10x zoom with VS2 clarity inclusions
10x zoom with VS1 clarity inclusions
10x zoom with VVS2 clarity inclusions
10x zoom with VVS1 clarity inclusions
10x zoom with IF clarity inclusions
10x zoom with FL clarity inclusions

Buying SI Diamonds

SI diamonds are very popular because even though they may have clarity characteristics that are eye visible, it’s not terribly distracting from sparkle. To the naked eye, diamond sparkle is slightly impacted and light performance is still quite high. Typically, only when the diamond grade is set by clouds or a single large inclusion, it can have a distracting impact. There are typically not structural problems that would cause chips or cracks in the diamond when set in jewelry, even if the inclusions are closer to the girdle. It is still advised that SI diamonds are set carefully be very experienced setters. While it’s not perfect, it’s certainly very respectable and valuable to have a SI diamond. Most often, no one will come close enough to even see or identify the inclusions. The value of SI diamonds will appreciate over time, like most other high quality diamonds. This is mainly due to their rarity and increase in diamond demand. Preference has generally shifted to quality over time, meaning consumers prefer quality over plain carat weight. We generally recommend not going below SI clarity, especially in larger diamonds as the imperfections get larger and are more like to be seen. In smaller carat diamonds (below 0.50ct), SI inclusions will not be eye visible.

You can buy SI quality diamonds from a variety of jewelers; however, the types of SI diamonds may differ for each jeweler. This is particularly important as the imperfections may be better or worse, depending on the jeweler’s inventory. With With Clarity’s diamond search, you’ll find the largest inventory for diamonds with SI1 and SI2 clarity at the right price. Please note that even the quality of our SI diamonds will vary as we cater to a variety of diamond budgets and preferences. Start by viewing With Clarity’s diamond search and pair the clarity with the other diamond 4 C’s to identify if SI is the right clarity range for you given your price range and budget. Like everything else, clarity is something you should balance and determine how important it is for you.

The next range below SI is I or included, meaning the diamond may have obvious inclusions. These diamonds tend to have imperfections that are clearly visible under 10x magnification, and often without 10x magnification, especially in larger diamonds (above 0.50ct).

Shop SI Diamonds