Platinum, like gold, can be alluvially transported from a lode and found in ore-grade sand deposits, so yes, conceivable, platinum ores can be found on the beach. Platinum nuggets from placer deposits are far rarer than gold nuggets and are highly valued by collectors.

Yes, garnet is a group of minerals with similar crystal structures but varying chemical compositions. Common characteristics include a vitreous luster, hardness ranging from 6.5 to 7.5 on the Mohs scale, and a wide range of colors such as red, green, and orange.