Tranquillite

Part of speech: noun

Definitions

1. A rare manganese silicate mineral that typically occurs in oxidized zones of manganese ore deposits
2. A mineral species containing manganese and silicate, found in metamorphic and hydrothermal settings
3. A manganese silicate mineral that crystallizes in orthorhombic forms and appears in manganese-rich geological environments

Etymology: English borrowed this spelling from Old French "tranquilité," which came from Latin "tranquillitas," meaning calm, stillness, or quiet. The spelling with the final "e" and double "l" is the Anglo-French form, and English later dropped the "e" and settled on "tranquility." The Latin noun is built from "tranquillus," "calm," which underlies the modern English adjective "tranquil." The Roman orator Cicero gave the Latin noun a more personal sense. In his philosophical writings, he used "tranquillitas animi," literally "tranquillity of mind," for the state of inner calm that Stoic and other Greek philosophers prized. The sense of a settled, untroubled mind is what the English noun carries when it describes a person's peace of mind rather than a quiet place or a calm sea.