An 
ionic crystal is a 
crystal which consists of 
ions bound together by their 
electrostatic[?] attraction. Examples of such crystals are the alkali halides, including potassium fluoride, potassium chloride, potassium bromide, potassium iodide, sodium fluoride, and other combinations of 
sodium, 
caesium, 
rubidium, or 
lithium ions with 
fluoride, 
bromide, 
chloride or 
iodide ions. Many other types of ionic crystals are known.
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