From Greek 'lithos' (stone) + 'sphaira' (sphere) — the rigid rocky outer layer of the earth, the 'stone sphere.'
The rigid outer part of the earth, consisting of the crust and upper mantle. The solid, rocky layer of the earth, as distinguished from the atmosphere, hydrosphere, and biosphere.
From Greek 'lithos' (λίθος, stone, rock) + 'sphaira' (σφαῖρα, sphere, ball, globe), a compound coined in scientific Latin in the 19th century as geologists systematically described the layered structure of the Earth. The Greek 'lithos' has a disputed PIE ancestry; some scholars connect it to *leyH- (stone, rock), others consider it a Mediterranean substratum word without clear Indo-European cognates. Greek 'sphaira' descends from PIE *sper- (to turn, to twist
The element lithium — the lightest metal, now critical for batteries in phones, laptops, and electric vehicles — was named from Greek 'lithos' (stone) because it was discovered in a mineral (petalite) rather than in plant material, as the related elements sodium and potassium had been. The 'stone' in lithium's name connects it etymologically to the lithosphere, the Neolithic period, and every megalith ever erected. The batteries powering the modern world