Calculate Gemstone Carat Weight

Gemstone Carat Weight Formula:

\[ Carat = \frac{Length \times Width \times Height \times SG}{2520} \]

Length:

Width:

Height:

Specific Gravity (SG):

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Carat Weight:

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1. What is Gemstone Carat Weight?

Carat weight is the standard unit of measurement for gemstones, where one carat equals 200 milligrams. This calculator estimates the carat weight of faceted gemstones based on their dimensions and specific gravity.

2. How Does the Calculator Work?

The calculator uses the gemstone carat weight formula:

\[ Carat = \frac{Length \times Width \times Height \times SG}{2520} \]

Where:

\( Carat \) — Gemstone weight in carats
\( Length \) — Length dimension in millimeters
\( Width \) — Width dimension in millimeters
\( Height \) — Height/depth dimension in millimeters
\( SG \) — Specific gravity (density relative to water)
\( 2520 \) — Conversion constant for mm³ to carats

Explanation: The formula calculates volume in cubic millimeters, multiplies by specific gravity to get mass, and converts to carats using the standard conversion factor.

3. Importance of Carat Weight Calculation

Details: Accurate carat weight estimation is crucial for gemstone valuation, jewelry design, and purchasing decisions. It helps determine the approximate weight before cutting or when precise weighing isn't possible.

4. Using the Calculator

Tips: Enter all dimensions in millimeters. Use accurate specific gravity values (e.g., 2.65 for quartz, 3.52 for diamond, 4.00 for corundum). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is specific gravity and why is it important?
A: Specific gravity is the ratio of a gemstone's density to water's density. Different gem materials have different SG values, which significantly affect the weight calculation.

Q2: How accurate is this calculation for faceted gemstones?
A: This provides an approximation. Actual weight may vary due to cut proportions, shape variations, and measurement precision. For round brilliants, more specialized formulas exist.

Q3: What are common SG values for popular gemstones?
A: Diamond: 3.52, Ruby/Sapphire: 4.00, Emerald: 2.72, Quartz: 2.65, Topaz: 3.53, Garnet: 3.5-4.3 depending on type.

Q4: Can this formula be used for all gemstone shapes?
A: It works best for rectangular or square shapes. For rounds, ovals, and other shapes, specialized formulas with shape factors are more accurate.

Q5: Why is the constant 2520 used in the formula?
A: 2520 is the conversion factor that accounts for the density of water and the carat-to-gram relationship, converting mm³ volume to carat weight.