Flawless (FL) – No internal clarity flaws. A stone is said to be flawless if no external or internal imperfections are visible under 10x magnification.
Internally Flawless (IF) – No internal flaws under 10x magnification
Both are very rare and priced accordingly
Very Very Slightly Included – Minute inclusions which are extremely difficult to find under 10x magnification. There are two grades within this category VVS1 and VVS2
Very Slightly Included – Minor inclusions which are difficult to find under 10x magnification. There are two grades within this category: VS1 and VS2
Slightly Included – Noticeable inclusions which are relatively easy to find under 10x magnification. There are typically two grades within this category: SI1 and SI2
Included – Obvious inclusions under 10x magnification. They are visible to the naked eye as well. There are typically two grades within this catagory: I1 and I2
Under the scrutiny of a jeweler’s 10x magnifying loupe or microscope, inclusions may be seen. These are nature’s birthmarks; they may look like tiny crystals, clouds or feather. The larger the inclusion, the lower the grade and the less rare the diamond.
The number, color, type, size, and position of surface and internal flaws affect a diamond’s value. Major inclusions can interfere with the path of light that travels through a diamond, diminishing its brilliance and therefore its value.
Virtually all diamonds have imperfections called inclusions and blemishes–scratches, trace minerals or other characteristics that can detract from the beauty of a diamond. Diamonds that are absolutely flawless are the most rare, and therefore, the most expensive.