noun
: a small bar of gold either pure or alloyed with silver in a known proportion for trying the fineness of a gold or silver article by comparing the streaks made by the article and the bar on a touchstone
noun
: a small bar of gold either pure or alloyed with silver in a known proportion for trying the fineness of a gold or silver article by comparing the streaks made by the article and the bar on a touchstone
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012