Bluestone refers to blue rocks. It is the most widely distributed gray or gray-white sedimentary rock in the crust. Can be used as building materials, tablets, etc. From Dong Fangshuo's Strange Classic of Nakano: There is a palace in the east, with bluestone as the wall, a silver plaque at the door and bluestone carving. Tang Bai Juyi's poem "Bluestone": Bluestone comes from Lantian Mountain and is transported to Chang 'an by car. This is the common name of limestone.
Limestone, referred to as limestone for short, is a carbonate rock with calcite as the main component. Sometimes it contains dolomite, clay minerals and clastic minerals, which are gray, off-white, gray-black, yellow, light red, brownish red and other colors. Hardness is generally not big, and there is a violent chemical reaction with dilute hydrochloric acid. Genetically, it belongs to sedimentary rocks.
Limestone is mainly formed in shallow sea environment. Limestone can be divided into granular limestone (transported by flowing water), biological skeleton limestone and chemical biochemical limestone according to its genesis. According to the structure, it can be subdivided into bamboo limestone, oolitic limestone, leopard limestone and massive limestone.
The main chemical composition of limestone is soluble CaCO3, so many stone forests and caves are formed in limestone areas, which are called karst topography. Limestone is the main raw material for burning lime and cement, and also the flux for ironmaking and steelmaking.
The rock structure of bluestone;
1, its structure is complex, and there are two kinds of structures: clastic structure and granular structure. The clastic structure is mainly composed of particles, micrite matrix and bright crystal cement.
2. Particles, also known as particles, mainly include internal debris, biological debris and oolitic particles. Mud crystal matrix is gypsum composed of calcium carbonate fine powder or crystals, the particles are mostly less than 0.05 mm, and bright crystal cement is chemical precipitation filled in the pores between rock particles, which is calcite crystal particles with a diameter greater than 0.0 1 mm; Grain structure is crystal particles precipitated by chemical and biochemical actions.