[header] How to clean onyx [title] Wipe the surface with a soft, damp cloth and mild soap. [step] 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. 
[title] Use a soft-bristled brush to remove crusted-on spills. [step] Harsh scrubbers can scratch onyx, so it's better to use a cleaning brush.