Diatomite is a kind of siliceous rock, which can be divided into two categories according to its genesis: biological or biochemical origin - diatomite, plate diatomite, protein soil, radiolarian rock and sponge rock.

Abiogenic (chemical, volcanic, secondary) - Jasper, chert, sillimanite, quartzite.

The main associated minerals in diatomite are clay minerals and carbonaceous (organic matter). When the content of these minerals reaches more than 50%, they belong to clay rock and carbonaceous shale, which is named diatom x rock. When the content of these minerals is less than 50%, they belong to diatomite, which is named x x diatomite.

The main mineral composition of diatomite is Opal and contains clay (kaolinite, water parent rock and a small amount of Jiaoling stone), carbonaceous (organic matter), iron (limonite, hematite and pyrite), carbonate minerals (calcite, dolomite and a small amount of siderite), quartz, muscovite, glauconite and feldspar.

Opal si02nh20 2, clay mineral, carbonaceous

Clay minerals and carbonaceous are the main associated minerals in diatomite. Clay minerals are distributed around diatom particles in the form of micro scales. When the content of clay minerals is the main component, it plays the role of cementing diatom. The carbonaceous materials are point shaped, massive or layered and coexist with diatomite. The carbonaceous materials are peat and lignite with low metamorphic degree and still retaining plant structure.

Diatomite decoration materials in Japan's building materials market mainly fall into three categories: one is natural dry products containing impure substances, which are cheap. The other is ordinary kiln fired products. It is first made of diatomite into plates and bricks of various shapes, and then fired at a high temperature of 800 ℃. It is a bit like ceramic tile, and the price is general. The third category is kiln fired products with various additives. This kind of high-grade products added with special materials use high-quality diatomite and add additives such as salt, soda ash or photocatalyst to remove impure organic matter, carbon and other substances in a kiln with a high temperature of about 1100 ℃, and burn them into all kinds of high-grade and gorgeous diatomite room decoration materials. Diatomite decoration materials sold in the Japanese market mainly include wall materials (plates), flooring materials, sanitary ware, ceiling materials, etc. In the Tokyo building materials market, the price of ordinary diatomite wall materials is more than 2000 yen per square meter (about 110 yen per dollar). Some companies have also developed a diatomite water-based coating, which can further strengthen the environmental protection effect of diatomite decoration materials.

Diatomite is a kind of rock with biological structure. It is mainly composed of 80 ~ 90% and some more than 90% diatom shells. The main consumer of silicon oxide in seawater and lake water is diatom, which constitutes diatom ooze. Diatomite is formed in the petrochemical stage in the diagenetic process.

Diatom shell is composed of opal. In the process of growth and reproduction, diatom absorbs colloidal silica in water and gradually transforms into opal.

The more diatom in diatomite and the less impurities, the whiter the color and lighter the quality. The specific gravity is generally 0.4-0.9. Because the diatom has many shell holes, the diatomite has a porous structure. The porosity of diatomite reaches 90-92%, with strong water absorption and sticky tongue. Due to the fine diatom particles, the diatomite is fine and smooth. Diatomite is insoluble in acid (HCl, H2SO4, HNO3), but soluble in HF and KOH.