The holes in this gauge are used to measure stones while the extensions are used to measure mountings. One side shows millimeters with corresponding carat measurements on the other.

Gauge with 4 arms for measuring diamonds.

Handy economical tool for measuring purposes. Available in metric and inches size. Moderately priced.

Brass vernier caliper 60 mm / 80 mm. Metal under plate eliminates the problem of holding gemstone while measuring. Graduated in matric and inch sizes.