crys·tal 
/ˈkrɪstl̟/ noun
plural crys·tals /ˈkrɪstl̟/ noun 1 [count] : a small piece of a substance that has many sides and is formed when the substance turns into a solid
▪ ice/salt crystals ▪ a crystal of quartz ▪ the crystal structure of minerals 2 : a clear hard mineral that is either colorless or very light in color and that is used in making jewelry [noncount] ▪ a necklace made of crystal [count] ▪ Some of the crystals used in the necklace are a pale pink color. 3 [noncount] a : a special type of glass that is very clear
▪ The wine glasses are made of the finest crystal. — often used before another noun ▪ a crystal chandelier/vase
b : objects made of this glass
▪ She inherited her mother's crystal. ▪ their wedding crystal 4 [count] US : the clear glass or plastic cover on a watch or clock
▪ I broke the crystal on my watch.
▪ ice/salt crystals ▪ a crystal of quartz ▪ the crystal structure of minerals
▪ The wine glasses are made of the finest crystal. — often used before another noun ▪ a crystal chandelier/vase
b : objects made of this glass
▪ She inherited her mother's crystal. ▪ their wedding crystal
▪ I broke the crystal on my watch.
