These are called striations.
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Parallel lines seen on crystal faces or cleavage planes are called growth striations. They are caused by variations in the crystal's growth rate or conditions during formation, resulting in alternating layers of different densities or compositions. These striations can provide valuable information about the crystal's growth history and conditions.
Parallel lines seen on cleavage planes or crystal faces are usually caused by twinning, where two crystals grow together with a specific orientation relationship. This twinning can result in repeated patterns of parallel lines that are visible on the surface of the crystal.
Fluorite exhibits perfect octahedral cleavage in three directions. This means that it is prone to breaking along flat surfaces parallel to the crystal faces of an octahedron.
Barium is an element which does not occur in pure (native) form on Earth. The two most common minerals in which barium occurs are Barite (BaSO4) and Witherite (BaCO3). According to its entry on wikipedia, Barite has Perfect cleavage parallel to base and prism faces: {001} Perfect, {210} Perfect, {010} Imperfect. I am unsure what sort of cleavage Witherite has.
Mineral crystal faces of varying luster and geometric shapes.
Rose quartz and smoky quartz are considered crystaline minerals due to their internal atomic arrangement, but they do not exhibit visible crystal faces because they often form in massive or granular structures rather than distinct crystal shapes. This lack of well-defined crystal faces is due to the specific conditions under which these minerals are formed in nature.