texture
Its texture.
the look and feel of sedimentary rocks are sometimes hard and smooth or hard and rough
The look and feel of a rock's surface, known as its texture, is primarily influenced by the size, shape, and arrangement of its mineral grains. Coarse-grained rocks have larger, visible crystals that can give a rough texture, while fine-grained rocks may feel smooth due to smaller, closely packed grains. The shape of the grains, whether angular or rounded, also affects the surface feel, with rounded grains often resulting in a smoother texture. Additionally, the pattern of grain arrangement can lead to varied visual appearances, such as layering or banding.
General physical appearance.
Rocks that feel and look the same likely share similar mineral composition and texture. Minerals present in the rock, as well as the way the rock formed (igneous, sedimentary, metamorphic), contribute to its appearance and feel. Thus, rocks that appear and feel the same are likely to be composed of similar minerals and have undergone similar geological processes.
Look at them. There shape, size, color and feel! Dont worry you will figure it out....
actual texture are the feel and look of a surface be it rough or smooth and seen as such
igneous rocks that form on earth's surface
Sedimentary rocks form on the Earth's crust, and can form metamorphic rocks when buried. Igneous rocks form under the surface, or when liquid magma reaches the surface as lava.
In my opinion for the fishes feel more in their real habitat and look good in a aquarium!
Lava.
Magma is under the surface of Earth's crust. Rocks on earth's surface are well ... on Earth's surface. Magma is also molten rock, not solid rock like the rocks on earth's surface.