National Buying antiques antique copper enamel

I acquired some high antique earthenware play 18701751061 Yin is the lowest level of the most primitive pottery, usually in a fusible clay manufacturing. Clinker or sand can also be added in some cases mixed with clay in order to reduce shrinkage. These products vary widely firing temperature, it should be based on the nature of the chemical composition of clay impurities contained in the number and availability. In the manufacture of bricks, such as porosity is too high, the body is not good frost resistance, low cross is not easy to hang mortar, so to keep the water absorption is generally between 5 and 15%. Color after firing blanks, decided colored oxide content and firing atmosphere, firing mostly yellow or red clay in the oxidizing flame, the firing is mostly blue or black in reducing flame.