Metals

Characteristics of Metals in Jewelry

• Definition of Metalsmiths: Bench jewelers are often referred to as metalsmiths due to their work with metals.

Key Properties of Jewelers' Metals

• Electrical Conductivity:

  • Jewelers' metals can conduct electricity.

  • Safety concern: Jewelry should be removed in certain industrial settings to prevent accidents.

  • Example: A woman suffered a shock and burn when her gold bracelet's safety chain contacted an electrical outlet.

• Light Reflection:

  • Metals like gold and silver reflect light, enhancing the aesthetic appeal of jewelry.

  • Proper polishing technique is crucial to maximize shine.

Important Metal Characteristics

• Malleability:

  • Definition: The ability of a metal to be hammered or rolled into sheets.

  • Gold is the most malleable metal; it can be stretched into a sheet of 100 square feet from just one ounce.

  • Sign makers utilize thin sheets of gold and silver, lighter than paper, for artistic purposes.

  • Other malleable metals: Aluminum and copper (not commonly used in fine jewelry).

• Ductility:

  • Definition: The ability to be drawn into a wire without breaking, retaining flexibility.

  • Gold and silver are highly ductile; one ounce of gold can produce over a mile of wire.

  • Use in electronics due to excellent conductivity of thin wires.

• Resistance to Oxidation:

  • Gold and silver resist reactions with oxygen and most acids, making them ideal for jewelry.

  • Their durability enhances their value and usability in jewelry making.

Historical Context and Metals in Coins

• Historical Use of Metals: Gold, silver, and copper have been used in coins for thousands of years, dating back to at least 450 B.C.

  • Gold coins were widely used until the 1930s, and silver was in U.S. coinage until 1965.

  • Gold backs the value of paper currency in many countries.

Coin Design Innovations

• Coin Edging:

  • The introduction of edged coins during the late Roman period was to combat the practice of "filing" metal from coins (making them lighter).

  • Edging prevents theft of precious metals and maintains coin value.

  • If the edging is removed or damaged, the coin is no longer considered valuable.

• Comparison of Ancient and Current Coins:

  • Ancient coins lacked a round edge; modern coins are designed to deter theft of metal.