Which term refers to a transparent measuring device divided into millimeters and tenths of a millimeter used to measure a diamond's table?

Which term refers to a transparent measuring device divided into millimeters and tenths of a millimeter used to measure a diamond's table?

• A. Tang
• B. Symmetry
• C. Table gauge
• D. Thermal tester

Answer: (C)

The table gauge is a transparent measuring device marked in millimeters and tenths of a millimeter, specifically built to measure the diamond’s table diameter. Placing it across the top facet lets you read the table width precisely, which is essential for calculating the table percentage—a proportion that influences how light is returned through the diamond and, ultimately, its cut quality. The other terms don’t serve this measurement purpose: tang isn’t a standard tool for gauging table size, symmetry is a grading attribute of facet alignment, and a thermal tester is used to identify diamond type rather than measure its dimensions.

The table gauge is a transparent measuring device marked in millimeters and tenths of a millimeter, specifically built to measure the diamond’s table diameter. Placing it across the top facet lets you read the table width precisely, which is essential for calculating the table percentage—a proportion that influences how light is returned through the diamond and, ultimately, its cut quality. The other terms don’t serve this measurement purpose: tang isn’t a standard tool for gauging table size, symmetry is a grading attribute of facet alignment, and a thermal tester is used to identify diamond type rather than measure its dimensions.