handsample

A handsample, also written as hand sample or hand specimen, is a small piece of rock, mineral, or fossil that can be held in the hand for direct examination. In field geology and mineralogy, handsamples are used for rapid visual and tactile assessment when mapping or describing an outcrop.

Typical handsample size ranges from about 1 to 10 centimeters. Observations focus on color, texture, grain size, mineral composition, and any visible structures such as layering, foliation, or veins. Physical properties such as hardness, luster, streak, cleavage, fracture, and transparency may be tested on the specimen or reported from prior measurements. Handsamples help distinguish rock types (igneous, sedimentary, metamorphic) and reveal textures such as phaneritic or aphanitic grains, coarse or fine sediment, or foliated metamorphic fabric.

In practice, a handsample is described in field notebooks or lab records with a concise description, measured dimensions, and a provisional identification. It is often photographed and labeled for later comparison with other samples collected from the same area. Handsamples are typically considered representative only of a small portion of a rock body; they may not capture full variability, so definitive identification or detailed understanding usually requires thin-section petrography, geochemical analysis, or broader sampling.

Terminology varies; the preferred terms in many geologic contexts are hand sample or hand specimen, with handsample appearing as an alternative form. See also core sample, petrography, and field geology.