Abbé refractometer can be used to measure both the refractive indexes of liquids and solids. In both cases, the refractive index of the substance must be lower than the refractive index of the glass used to made measuring prism.

Agate is one of the most common materials used in the art of hardstone carving and has been recovered at several ancient sites, indicating its widespread use in the ancient world, for example, archaeological recovery at the Knossos site on Crete illustrates its role in Bronze Age Minoan culture.

An Altimeter is an instrument used to measure the altitude of an object above a fixed level. Altitude can be determined based on the measurement of atmospheric pressure. An altimeter is the most important piece of skydiving equipment, after the parachute itself. Altitude awareness is crucial at all times during the jump, and determines the appropriate response to maintain safety.

Alumina (Aluminium Oxide) is the most widely used oxide ceramic material. Its applications are widespread and include spark plugs, tap washers, abrasion-resistant tiles, and cutting tools.