Hälleflinta (a Swedish word meaning rock-flint) is a white, grey, yellow, greenish or pink fine-grained rock consisting of an intimate mixture of quartz and feldspar. Many examples are banded or striated; others contain porphyritic crystals of quartz which resemble those of the felsites and porphyries. Mica, iron oxides, apatite, zircon, epidote and hornblende may also be present in small amount.