Quartz refers to a family of crystalline gemstones of various colors and sizes. Among the well-known types of quartz are rose quartz (which has a delicate pink color), and smoky quartz (which comes in a variety of shades of translucent brown). A number of other gemstones - like Amethyst and Citrine - are also part of the quartz family. Rutilated quartz is a popular type of quartz containing needle-like inclusions.