What is quartz stone quartz stone? Quartz no radiation, high hardness quartz plate, creating a quartz stone countertops scratch without spending (Mohs hardness 7); sewage is not stained (vacuum manufacturing dense nonporous.);. Hot is not bad (quartz material can be temperature 300 ℃ ); with not old (30 polishing process without maintenance); non-toxic radiation (NSF certification quartz uses no heavy metals, may be in direct contact with food). What is quartz stone quartz stone? Home decoration (kitchen countertops, sink, kitchen walls, tables, coffee table, window sills, door pockets, etc.) in the field, is a non-radioactive contamination, reusable green, green building new indoor decoration materials. Quartz countertops | quartz | Kai Sa Building Materials provided by Dongguan Kai Sa Building Materials Limited. Building Materials Co., Ltd., Dongguan City, Kai Sa (www.kaisa-stone.com) strong, credible, in Dongguan, Guangdong sandstone industry has accumulated a large number of loyal customers. The company better work attitude and constantly improving Kai Sa innovative ideas will lead into the glorious building materials and you work for a better future!