Jeweler's scale and caliper

In jewelry everything is weighed and measured. The scale and caliper allow the metal, price and stone sizes to be calculated.

Scale #

Precision, with resolution of 0.01 g or better, and able to weigh in grams, carats and other units. For gems a carat (0.2 g) is used.

Caliper (vernier) #

Measures diameters, thicknesses and depths in millimeters, with accuracy to tenths.

Units #

Gold can be expressed in grams or troy ounces (31.1 g); gems in carats; and a point equals one hundredth of a carat.

Calibration #

Check with standard weights and place the scale on a stable surface, free of drafts.

What is weighed and why #

The jeweler weighs metal before melting to calculate the price and the alloy, the finished piece to know how much metal it holds, and gems in carats. Weighing before and after filing shows how much metal was lost.

How to use the scale #

Place it on a stable surface, free of drafts; let it settle, tare the container and weigh. Check calibration with a standard weight now and then.

Weights and equivalents #

• 1 g = 5 carats (gem).
• 1 troy ounce = 31.1 g.
• 1 carat = 100 points = 0.2 g. See carat of gems and karats of gold.

The caliper (vernier) #

It measures diameters and thicknesses to a tenth of a millimeter. It is used to measure the thickness of a sheet or wire, the diameter of a stone and the width of a band.

See also #

• Metal ingots and casting grain
• Jewelry hallmarks and stamps: what 925, 750 or 585 mean