Yes m that it true, other than glasses all rocks have grains.
Rough-textured rocks have distinct grains that are visible to the naked eye. These grains are typically made up of mineral crystals or fragments that give the rock its rough texture. The size, shape, and arrangement of grains can provide important clues about the rock's formation and history.
large grains
Rocks with a large grain size perhaps with angular grain shapes.
A schistose texture.
A coarse texture refers to a surface that is rough or uneven to the touch. This can be visually identified by larger particles or grains that make up the material. Materials like gravel, sandpaper, or certain fabrics can possess a coarse texture.
Coarse grained textured rocks (phaneritic) have very large crystals because the magma, from which they are created, cools very slowly. Fine grained rocks (aphaneritic) have small crystals because the lava, from which they are created, cools down very quickly.
Texture in rocks is not the same as color or shape. Texture refers to the size, shape, and arrangement of mineral grains or crystals within a rock, while color refers to the outward appearance of the rock. Similarly, shape in rocks refers to their physical form or structure, and not the internal arrangement of mineral grains which defines texture.
The grains of constituent compounds and their grain size.
Coarse-grained phaneritic rocks have mineral grains that are large enough to be seen with the naked eye, giving them a rough texture. Fine-grained aphaneritic rocks have much smaller mineral grains that are not individually visible, resulting in a smooth or fine texture.
Fine textured rocks have a fine-grained or aphanitic texture, meaning that their mineral crystals are too small to be visible to the naked eye. This texture forms when the rock cools quickly, preventing large mineral crystals from growing. Fine-grained rocks often have a smooth, uniform appearance.
The main types of rock texture are crystalline, fragmental, glassy, and vesicular. Crystalline rocks have interlocking mineral grains, fragmental rocks are made up of broken fragments of pre-existing rocks, glassy rocks have no crystal structure due to rapid cooling, and vesicular rocks have cavities or bubbles caused by gas escaping during solidification.
they stick to rocks and have a spiky rough texture