Ever heard of
sandstone, or better yet, quartz?

SANDSTONE,
coarse-grained, sedimentary rock consisting of consolidated masses of sand deposited by moving water or by wind. The chemical constitution of sandstone is the same as that of sand; the rock is thus composed essentially of quartz. The cementing material that binds together the grains of sand is usually composed of silica, calcium carbonate, or iron oxide. The color of the rock is often determined largely by the cementing material, iron oxides causing a red or reddish-brown sandstone, and the other materials producing white, yellowish, or grayish sandstone.
QUARTZ,
most common of all minerals, composed of silicon dioxide, or silica, SiO 2 It is distributed all over the world as a constituent of rocks and in the form of pure deposits. It is an essential constituent of igneous rocks such as granite, rhyolite, and pegmatite.... Sandstone, a sedimentary rock, is composed mainly of quartz.... Quartz is also the primary constituent of sand....
Quartz crystals exhibit a property called the piezoelectric effect, that is, they produce an electric voltage when subjected to pressure along certain directions of the crystal.
Hmmmm.... interesting... electrically charged kran.