Premium Gold Test Stone-Made in the USA 3" x 1-5/8" x 1/4"

A professional-grade gold testing stone made in the USA from natural Arkansas black novaculite, quarried and cut domestically. Used by jewelers and metalsmiths to test precious metals, this stone—also known as a streak stone or touchstone—provides a reliable surface for acid-based karat testing. Beware of cheap imitations made of glass, which stain and degrade quickly under repeated use.

To test a metal item, rub or scratch it across the stone's surface, then apply testing acid (sold separately) to the rubbing. An experienced user can determine the metal type based on the acid's reaction. For comparative karat testing, rub a known gold testing needle or verified gold sample alongside the test item's rubbing, apply acid to both, and compare the reactions—a similar reaction indicates similar karat content.

Features

• Made in the USA from natural Arkansas black novaculite
• Quarried and cut domestically for consistent quality
• Suitable for acid-based precious metal testing
• Also known as a streak stone or touchstone
• Supports both reaction-based and comparative karat testing methods
• Resists staining and degradation—unlike glass imitations

Specifications

Notes

• Testing acid is sold separately and is required for acid-based testing.
• Gold testing needles or verified gold samples are required for comparative karat testing.
• Accurate results depend on the experience of the user performing the test.