From Latin 'calx' (pebble/limestone), the same root that gave us calcium, calculate, and calculus.
A soft white limestone composed of the skeletal remains of marine microorganisms, used for writing and in construction.
From Old English 'cealc,' from Latin 'calx' (limestone, pebble), from Greek 'khalix' (pebble, gravel). The Latin 'calx' also gave us 'calcium,' 'calculate' (from counting with pebbles), and 'calculus.' Key roots: khalix (Greek: "pebble, small