A dark fine-grained → igneous rock typically composed of → plagioclase with → pyroxene and → olivine and often displaying a columnar structure.
From L.L. basaltes, misspelling of L. basanites "very hard stone," from Gk. basanites, from basanos "touchstone," from Egyptian baban "a stone used by the Egyptians as a touchstone of gold."
1) A crystalline compound, sodium chloride, NaCl, occurring as a mineral, used for
food seasoning and preservation.
O.E. sealt; cf. O.N., O.Fris., Goth. salt, Du. zout, Ger. Salz from PIE *sal- "salt;" cf. Gk. hals (genitive halos) "salt, sea;" L. sal; O.Ir. salann; Welsh halen; O.C.S. sali "salt."
Namak "salt;" Mid.Pers. namak "salt."
Fr.: doigts de sel
Oceanography: One of several alternating columns of rising and descending water resulting from a → mixing process that occurs when warm salty water overlies a colder and relatively fresher layer of water. If the overlying salty water loses enough heat, it sinks down into the colder, fresher water, lengthening into a finger of salty water. Becuse the finger loses heat faster than it loses salt, the salt finger will continue to sink (salty water is denser than fresh water of the same temperature). Hence the salt finger loses more heat and displaces the colder water around it, which rises up and mixes into the warm salty layer above. Salt fingers are an example of → double-diffusive convection and play an important role in oceanic mixing. See also → fingering instability, → fingering convection.
A chemical compound, potassium nitrate, KNO3. It is a naturally occurring mineral source of nitrogen, and is used in the manufacture of fireworks, fluxes, gunpowder, etc.
M.E. sal peter, salpetre, from O.Fr. salpetre, from M.L. sal petrae "salt of rock," from L. sal, → salt + petra "rock, stone."
Šuré, related to šur "salty;" Mid.Pers. šôr "salty," šorag "salt land;" cf. Skt. ksurá- "razor, sharp knife;" Gk. ksuron "razor;" PIE base *kseu- "to rub, whet."