The distinction rests on whether the article carries an actual plating of gold, silver, or another precious metal. A base metal ornament with a gold-tone lacquer or paint finish does not qualify as precious-metal plated and falls under 830629, while one with a genuine electroplated precious-metal layer classifies under 830621.

Even if a bell or gong is primarily decorative, it classifies under 830610 (signaling devices) rather than the ornaments subheadings, because the heading text specifically names bells and gongs as a distinct group. Only articles whose sole function is decorative — with no signaling use — would be considered for the ornaments subheadings.