What are whitish-gray stones with a nonmetallic luster that leave a colorless streak?

Whitish-gray stones with a nonmetallic luster that leave a colorless streak are likely to be varieties of minerals such as quartz or feldspar. These minerals often exhibit a light color and can be found in many geological environments. Their nonmetallic luster and ability to leave a colorless streak are characteristic features used to identify them in mineralogy. Further examination, including hardness and crystal structure, would help in precise identification.