Quartz itself is transparent or transluscent. But trapped impurities such as iron, copper, etc give quartz a full rainbow of colors to choose from.
Impurities gives quartz its many beautiful colors.
Quartz is a color.
Quartz has a white streak.
Rainbow quartz is a term used for describeing two states of quartz crystal. One state, is a quartz crystal that has been fractured internally. The refraction of light through the crystal, produces a rainbow color spectrum. The second state, are quartz crystals that have been coated in titanium. The coating gives the surface of the quartz a rainbow effect.
Pure quartz is a colorless mineral, and so a pure quartz sandstone will appear white due to multiple reflections and refractions between grains. However, impurities in the sandstone may give it some other color. What color it turns out as depends on the impurities. For example, iron oxide will produce a red sandstone.
Impurities gives quartz its many beautiful colors.
White. All forms of quartz will have a white streak, regardless of specimen color.
Amethyst is a violet form of quartz.
White.
Quartz is colorless when pure, but can be found in all colors of the rainbow.
White.
pink