Product Parameters Product Name: Others Origin: Lianyungang, Jiangsu Silica Content: 99.99% Melting Point: 1730°C Mohs Hardness: 6-7 Product Features Lianyungang Hibo Quartz Products Co., Ltd. is one of the major manufacturers of quartz glass tubes in China, located in the Donghai County Economic Development Zone of Jiangsu Province, known as the "Land of Crystal."