Rockcrystal

n. transparent colourless quartz, usu. in hexagonal prisms. rocker n. 1 curved bar etc. on which something can rock. 2 rockingchair. 3 devotee of rock music, esp. a leatherclad motor cyclist. 4 a device for rocking. b pivoted switch operating between ‘on’ and ‘off positions. off one’s rocker slang crazy.