Old English cealc "chalk, soft white limestone; lime, plaster; pebble," a West Germanic borrowing from Latin calx (2) "limestone, lime (crushed limestone), small stone," from Greek khalix "small pebble," which many trace to a PIE root for "split, break up."
Cognate words in most Germanic languages still have the "limestone" sense, but in English transferred chalk to the opaque, white, soft limestone found abundantly in the south of the island. The modern spelling is from early 14c. The Latin word for "chalk" was creta, which also is of unknown origin. With many figurative or extended senses due to the use of chalk marks to keep tracks of credit for drinks in taverns and taprooms, or to keep the score in games.
rock resembling sandstone, 1803, from German Wacke, from Middle High German wacke "large stone, rock projecting from the surface of the ground," from Old High German wacko, waggo "gravel, pebble, rock rolling in a riverbed," which probably is from Old High German wegan "to move" (from Proto-Germanic *wag- "to move about," from PIE root *wegh- "to go, move"). A miner's word, brought into geology by German geologist Abraham Gottlob Werner (1750-1817).
late 14c., "art, manner, or practice of computing by numbers," also "the process of making a horoscope," from Late Latin calculationem (nominative calculatio) "a computation, calculation, reckoning," noun of action from past-participle stem of calculare "to reckon, compute," from Latin calculus "reckoning, account," originally "pebble used in counting," diminutive of calx (genitive calcis) "limestone" (see chalk (n.)). From early 15c. as "the result of reckoning, the solution for a problem."
In medicine, the word also has been used from 1732 to mean kidney stones, etc., then generally for "concretion occurring accidentally in the animal body," such as dental plaque.
as in conk out, 1918, coined by World War I airmen, perhaps in imitation of the sound of a stalling motor, reinforced by conk (v.) "hit on the head," originally "punch in the nose" (1821), from conk (n.), slang for "nose" (1812), perhaps from fancied resemblance of the nose to a conch (pronounced "conk") shell. Perhaps also imitative: Compare Greek konk, a syllable representing the sound made by a pebble striking the bottom of the (metal) voting urn [William Smith, "Dictionary of Greek and Roman Antiquities"].
colorless imitation stone of paste or leaded glass, 1879, a loan-translation of French caillou du Rhin "Rhine pebble," so called because they were made near Strasburg, on the River Rhine, and invented there 1680s. Extensively worn later 18c. and popular thereafter.
Rhinestone jewelry, a reproduction of the ornaments of the Louis XV. period, is all the rage in Paris. The Rhinestones are as brilliant as diamonds, and being set in silver, will stand any amount of wear or of cleaning. [The American Stationer, March 20, 1879]
general name for the hard, calcareous skeleton excreted by certain marine polyps, c. 1300, from Old French coral (12c., Modern French corail), from Latin corallium, from Greek korallion, a word perhaps of Semitic origin (compare Hebrew goral "small pebble," Arabic garal "small stone").
Originally especially the red variety found in the Mediterranean, used ornamentally, hence "red, the (red) color of coral" (mid-15c.). As an adjective, "made of coral," mid-15c. The coral-snake (1760) is so called for the red zones in its markings. Coral-reef is attested from 1745 (see reef (n.1)).
1836, "old-fashioned," from French rococo (19c.), apparently a humorous alteration of rocaille "shellwork, pebble-work" from roche "rock," from Vulgar Latin *rocca "stone." Specifically of furniture or architecture of the time of Louis Quatorze and Louis Quinze, from 1841. If this etymology is correct, the reference likely is to the excessive use of shell designs in this lavish style. For differentiation, see baroque. The general sense of "tastelessly florid or ornate" is from 1844. As a noun, "rococo ornamentation or style," by 1840.
Much of the painting, engraving, porcelain-work, etc., of the time has, too, a real decorative charm, though not of a very high order in art. Hence rococo is used attributively in contempt to note anything feebly pretentious and tasteless in art or literature. [Century Dictionary, 1897]
Sense of "testicle" is from late Old English. The British measure of weight (usually equal to 14 pounds) is from late 14c., originally a specific stone. Stone-fruit, one with a pit, is from 1520s. Stone's throw for "a short distance" is attested from 1580s. Stone Age is from 1864. To kill two birds with one stone is first attested 1650s. To leave no stone unturned is from 1540s.