formerly also cristal, and, erroneously, chrystal, Old English cristal "clear ice; clear, transparent mineral," from Old French cristal (12c., Modern French crystal), from Latin crystallus "crystal, ice," from Greek krystallos, from kryos "frost," from PIE root *kreus- "to begin to freeze, form a crust."

The spelling adopted the Latin form 15c.-17c. The mineral has been so-called since Anglo-Saxon times; it was regarded by the ancients as a sort of petrified ice. In the specific sense in chemistry, "body with a molecular structure that causes it to take the form of a regular solid enclosed by a certain number of plane surfaces," from 1620s.

Crystall is a brighte stone and clere with watry colour. Men trowe that it is of snowe or yse made harde in space of many yeres. Therfore the Grekes yave a name therto. It is gendred in Asia and in Cipres, and namely in the northe moutaynes where the sonne is mooste feruent in somer. [Bartholomew Glanville, "De proprietatibus rerum," c. 1240, translated by John of Trevisa c. 1398]

A top-20 name for girls born in the U.S. between 1978 and 1984. As a shortened form of crystal-glass it dates from 1590s. As an adjective, from late 14c. Crystal ball is from 1794.  Rock-crystal is the general name for transparent crystals of quartz. Crystal Palace was the name of the large building, made chiefly of glass and iron, for the universal exhibition of 1851 in London's Hyde Park.

"science of the process of crystallization and of the forms and structures of crystals," 1802, from French crystallographie (1772); see crystal + -graphy. Related: Crystallographic; crystallographer.

1590s, "convert into crystal;" 1660s "form into crystals;" from crystal + -ize. Intransitive sense of "be converted into crystals" is from 1640s. Figurative use, of opinions, love, etc., that are at first indeterminate, "assume a definite form and fixity," is from 1660s. Related: Crystallized; crystallizing.

late 14c., "made of or like crystal;" c. 1400, "resembling crystal, pure, clear, transparent," from Old French cristalin "like crystal" (Modern French crystallin) and directly from Latin crystallinus, from Greek krystallinos "of crystal," from krystallos (see crystal). Related: Crystallinity.

"divination by means of crystals," 1610s; see crystal + -mancy.

The operator first muttered over the crystal (a beryl was preferred) certain formulas of prayer, and then gave it into the hands of a young man or a virgin, who thereupon, by oral communication from spirits in the crystal, or by written characters seen in it, was supposed to receive the information desired. [Century Dictionary]

c. 1600, "made into crystal;" 1660s, "formed into crystals," past-participle adjective from crystallize. Of fruit, etc., "preserved by sugar (and usually coated with sugar crystals), by 1875.