The GIA clarity scale is the global standard and ranges from FL (Flawless) down to I3 (Included). The most common diamonds in Scandinavian jewelry fall in the VS (Very Slightly Included) to SI (Slightly Included) range – an excellent interval offering good brilliance at reasonable prices.

• FL (Flawless): No inclusions or surface defects under 10x magnification. Extremely rare – under 1% of all diamonds. Large price difference vs IF with no visible difference.

• IF (Internally Flawless): No inclusions, but may have minor surface defects. Nearly as rare as FL.

• VVS1 & VVS2 (Very Very Slightly Included): Extremely difficult to detect, even for experts with a loupe. Minimal impact on brilliance. Sought after by collectors.

• VS1 & VS2 (Very Slightly Included): Visible to trained eyes under 10x magnification but never to the naked eye. Excellent choice – high quality without paying top price.

• SI1 & SI2 (Slightly Included): Clear under 10x magnification. SI1 is often 'eye-clean' and offers excellent value. SI2 can sometimes have visible inclusions depending on placement.

• I1, I2 & I3 (Included): Visible to the naked eye. I1 can still be aesthetically pleasing, I2 and I3 noticeably affect brilliance and may have structural weaknesses.

The trade uses the term 'eye-clean' for diamonds whose inclusions are not visible to the naked eye at a normal viewing distance (~30 cm / 12 inches). VS1 is always eye-clean. SI1 usually is. SI2 varies – an inclusion directly under the table (top facet) is more visible than one near the edge under a bezel. At MittGuld, we always assess the actual brilliance, not just the grade stamp.