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How to clean onyx
Wipe the surface with a soft, damp cloth and mild soap.
Regular household cleaners are often acidic and can damage onyx. Milder soaps are ideal, such as dish detergent or soaps labeled " green, " which are usually ph-neutral.
Use a soft-bristled brush to remove crusted-on spills. Harsh scrubbers can scratch onyx, so it's better to use a cleaning brush.