The 4 C's of Diamond Quality
Understanding diamond quality is essential for making informed decisions. Learn how the 4 C's determine a diamond's value and beauty.
Diamond Quality Education
The Diamond Institute of America's color grading scale and quality assessment follows industry-standard practices. Each diamond characteristic represents a specific aspect of quality that affects the stone's appearance and value.
Understanding these factors helps you make informed decisions when purchasing or appraising diamond jewelry.
Color
The Diamond Institute of America's color grading scale starts at D and goes through Z. Each letter grade represents a range of color, rather than one specific color.
Color Grading Scale:
Colorless
Near Colorless
Faint Yellow
Light Yellow
Key Points:
- D is the highest color grade (most colorless)
- Each grade represents a range, not a specific color
- Color differences can significantly affect value
Clarity
Diamonds have internal features, called inclusions and surface irregularities, called blemishes. Together, they're called clarity characteristics. A diamond's clarity grade is based on the relative absence of clarity characteristics.
Clarity Grading Scale:
| FL | Flawless |
| IF | Internally Flawless |
| VVS1-VVS2 | Very Very Slightly Included |
| VS1-VS2 | Very Slightly Included |
| SI1-SI2 | Slightly Included |
| I1-I3 | Included |
Key Points:
- FL and IF diamonds are extremely rare
- Most diamonds fall within SI1-SI2 range
- Clarity affects brilliance and value
Cut
A diamond's cut determines how much light the stone reflects. When a diamond is cut to proper proportions, maximum light is returned through the top of the diamond.
Cut Quality Grades:
- Excellent: Maximum brilliance
- Very Good: High brilliance
- Good: Standard brilliance
- Fair: Lower brilliance
- Poor: Minimal brilliance
Cut Factors:
• Table percentage• Crown angle
• Pavilion depth
• Girdle thickness
• Culet size
Key Points:
- Cut is the most important factor for brilliance
- Poor cut can make expensive diamonds look dull
- Excellent cut maximizes fire and scintillation
Carat Weight
Carat is the standard unit of measurement for diamonds. One carat equals 200 milligrams or 0.2 grams. Carat weight is divided into 100 points.
Popular Carat Weights:
| Weight | Points | Description |
|---|---|---|
| 0.25 ct | 25 points | Quarter carat |
| 0.50 ct | 50 points | Half carat |
| 0.75 ct | 75 points | Three-quarter carat |
| 1.00 ct | 100 points | One carat |
| 2.00 ct | 200 points | Two carats |
Key Points:
- Price increases exponentially with carat weight
- Rare sizes command premium prices
- Cut quality affects apparent size
Popular Diamond Shapes
While the 4 C's determine quality, diamond shape is a matter of personal preference. Each shape has unique characteristics and beauty.
Round Brilliant
Classic and most popular cutPrincess
Square with brilliant facetingEmerald
Rectangular with step cutsOval
Elongated brilliant cutMarquise
Boat-shaped with pointsPear
Teardrop shapeCushion
Square with rounded cornersHeart
Romantic heart shape4 C's Comparison Guide
| Factor | What It Affects | Price Impact | Visibility |
|---|---|---|---|
| Color | Overall appearance and warmth | High | Easily noticed in lower grades |
| Clarity | Brilliance and transparency | Medium-High | Often requires magnification |
| Cut | Fire, brilliance, and scintillation | Very High | Immediately apparent |
| Carat | Size and presence | Very High | Obvious to naked eye |
Need a Professional Appraisal?
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