COUNTERTOPS & SLABS Explore our expansive selection of slabs and countertops available for your project. In addition to granite, marble, travertine, limestone, slate, and Q Premium Natural Quartz, we also carry prefabricated countertops. Select the MSI Countertop Selection Guide if you’re looking for ideas. This handy tool will help you from start to finish with product information, design tools to envision your kitchen and actual slabs available at the MSI warehouse closest to you.