Gemstone Clarity Explained: What You Need to Know

Clarity measures how free a gemstone is from internal flaws (inclusions) and surface blemishes. While the 4 Cs make clarity central to diamond grading, clarity affects all gemstones differently. Understanding clarity helps you make smarter purchases.

How Clarity Is Graded in Diamonds

The GIA diamond clarity scale runs from Flawless to Included:

• FL (Flawless): No inclusions or blemishes visible at 10x magnification. Extremely rare and expensive
• IF (Internally Flawless): No inclusions, only minor surface blemishes at 10x
• VVS1-VVS2 (Very Very Slightly Included): Inclusions so small they are difficult to see at 10x magnification
• VS1-VS2 (Very Slightly Included): Minor inclusions visible at 10x but not to the naked eye. Best value
• SI1-SI2 (Slightly Included): Inclusions noticeable at 10x, sometimes visible to the naked eye
• I1-I3 (Included): Inclusions visible to the naked eye. May affect brilliance or durability

The Sweet Spot: VS and SI Grades

For most buyers, VS1-SI1 offers the best balance of quality and value:

• VS1-VS2 diamonds appear identical to Flawless diamonds to the naked eye
• SI1 diamonds may have tiny visible inclusions that are practically invisible in a setting
• The price difference between VVS and VS can be 20-30% for the same visual appearance
• Spending on clarity beyond what the eye can see means paying for a certificate, not beauty

Clarity in Colored Gemstones

Unlike diamonds, colored gemstones have different clarity expectations by type:

Type I — Typically Eye-Clean

These stones are expected to be free of visible inclusions:

• Aquamarine, Topaz, Tanzanite, Citrine
• Visible inclusions in these stones significantly reduce value

Type II — Usually Included

Minor inclusions are common and accepted:

• Ruby, Sapphire, Garnet, Tourmaline, Peridot
• Eye-clean stones in this category command premium prices

Type III — Almost Always Included

Inclusions are part of the stone’s character:

• Emerald, Morganite (some varieties)
• A flawless emerald is astronomically expensive. Most have visible inclusions called “jardin” (garden) that are considered part of their beauty

Inclusions That Add Value

Some inclusions are actually desirable:

• Star effect (asterism): Needle-like inclusions in sapphires and rubies create a star pattern
• Cat’s eye (chatoyancy): Parallel inclusions create a moving line of light
• Color zoning: Can create interesting patterns in sapphires and tourmaline
• Silk in rubies: Fine needle inclusions can actually improve the appearance by softening the color and adding a velvety quality

Clarity and Durability

Large inclusions that reach the surface can weaken a stone. This matters most for:

• Rings that receive daily impact and friction
• Softer stones (under 7 on Mohs scale) that are already prone to damage
• Emeralds with large surface-reaching fissures

Practical Buying Tips

• For diamonds: Buy VS2 or SI1 and invest the savings in a better cut. Cut affects sparkle more than clarity
• For colored stones: Prioritize color and cut. Clarity is less important when the stone has rich, saturated color
• Ask for photos: When shopping online, always request or examine close-up photos showing any inclusions
• Moissanite and CZ: Lab-created stones typically have excellent clarity at a fraction of the cost

Shop Gemstones at Biovlia

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