Acid test

Figuratively, the term represents any definitive test for attributes, such as gauging a person's character or evaluating a product's performance.

The procedure includes rubbing the gold-colored item on black stone, leaving a visible mark.

[2][3][4][5] In geological applications, detecting the presence of calcite or other forms of calcium carbonate in alkaline soils or during lithological analysis involves using dilute hydrochloric acid and observing effervescence.

Financial analysts also employ the "acid test" nickname for the quick ratio method, which assesses the liquidity of a business.

The term "acid test" took on a different meaning in the realm of experiences with the psychedelic drug LSD,[9] popularized by the Merry Pranksters.