Which metals are precious metals and how are heavy and light precious metals distinguished?

Precious metals are metals that have a high economic value and are relatively scarce. Major precious metals include gold, silver, platinum and palladium. Typically, precious metals are characterized by being relatively non-corrosive, having good electrical and thermal conductivity, and are widely used in industry and jewelry making.

Heavy and light precious metals are usually distinguished based on the density of the metal:

1. Heavy Precious Metals: Generally refers to the denser precious metals, which mainly include platinum and palladium. Both platinum and palladium are silvery-white metals that are denser and therefore categorized as heavy precious metals.

2. Light Precious Metals: generally refers to the less dense precious metals, mainly including gold and silver. Gold is the lightest precious metal, while silver is slightly heavier, but still light relative to platinum and palladium.

This classification is made primarily from the perspective of density, since density is the ratio of the mass to the volume of a substance, and precious metals are used in many applications, such as jewelry and coin making, where density can have an impact on their appearance and use.

It is important to note that this type of categorization is mainly used for simple distinctions, and in practice, precious metals may also be categorized with respect to a number of factors, such as their chemical properties, their uses, and so on.