Everything is fine. Slightly acidic mineral rocks and volcanic rocks are good. Volcanic rocks and slightly acidic minerals have their own advantages, and which one to choose depends on specific needs. Volcanic rocks are formed by the cooling and solidification of volcanic magma or volcanic ash during volcanic eruption. They are usually gray, black or brown with holes and bubbles. They are light and porous and easy to carve and polish. Slightly acidic ore refers to minerals occurring in water-bearing deposits, which are usually composed of sulfides, oxides and carbonates of metals such as copper, iron, magnesium and lead, and their colors are mostly gray, black and blue. Micro-acid ore is a heavy mineral with hard texture, which is sometimes used as jewelry and decorative materials.