SI1 vs SI2 Diamonds

SI1 vs SI2 Diamonds

Diamonds graded SI1 and SI2 fall within the Slightly Included (SI) clarity category on the diamond clarity scale.

These diamonds contain inclusions that are visible under 10× magnification, but depending on their size and location, they may still appear clean to the naked eye.

Because diamonds within the SI clarity range can vary significantly in appearance, careful selection is especially important.

a loose round brilliant cut diamond and a princess cut diamond

What Is an SI1 Diamond?

An SI1 diamond contains inclusions that are visible under 10× magnification but are often difficult to detect without magnification.

When carefully selected, many SI1 diamonds appear completely eye-clean, meaning that inclusions cannot be seen during normal viewing.

This clarity grade is widely considered an excellent balance between beauty, rarity and value, particularly for engagement rings.

What Is an SI2 Diamond?

An SI2 diamond contains inclusions that are slightly more noticeable under magnification and may sometimes be visible without magnification depending on their size or position within the diamond.

However, well-selected SI2 diamonds can still appear clean and beautiful when viewed normally, particularly when inclusions are located near the edges of the stone or hidden beneath facets.

Why Selection Matters

The SI clarity range shows some of the greatest variation between diamonds.

Two SI2 diamonds may appear completely different depending on:

• the size of the inclusions
• where they are located within the diamond
• the transparency of the stone
• the quality of the diamond cut

For this reason, certificate grading should always be considered a guide rather than the sole measure of quality.

A poorly graded SI1 diamond may display visible inclusions, while a carefully selected SI2 diamond may appear perfectly clean.

Eye-Clean vs Visible Diamonds

When selecting a diamond within the SI clarity range, the most important consideration is whether the diamond appears eye-clean.

An eye-clean diamond means that inclusions cannot be seen without magnification during normal viewing.

This is why physically viewing a diamond is so valuable. A diamond may carry the same clarity grade on paper but present very differently when examined in person.

The MDT DESIGN Perspective

At MDT DESIGN, every diamond we offer is personally inspected by our jewellers.

If we determine that inclusions are visible to the naked eye, we will not stock or sell that diamond, regardless of its certificate grading.

For this reason, we carefully select SI1 and exceptional SI2 diamonds that meet our eye-clean standard and deliver outstanding beauty.

When chosen correctly, SI diamonds can provide exceptional brilliance and value while still appearing beautifully clean.

Looking for Your Perfect Diamond?

Choosing the right clarity grade can make a significant difference to both the beauty and value of your diamond.

If you would like expert guidance when selecting your diamond, we invite you to contact MDT DESIGN to arrange a private diamond consultation with our experienced jewellers.