Flintstone Marble & Granite | Quartz, Granite, Marble Countertops ... Countertop Contractors, Fabricators, Installers. As a leading countertop contractor in Montgomery county MD with over ten years’ experience in the kitchen countertop industry, Flintstone Marble and Gr Countertop Contractors, Fabricators, Installers. As a leading countertop contractor in Montgomery county MD with over ten years’ experience in the kitchen countertop industry, Flintstone Marble and Granite provides every type of countertop to make your kitchen the best place in your home. Whether you want quartz countertops or marble countertops, …