Precious Metals

Platinum

Platinum comes from the Spanish word “platina,” which means little silver, because it was mistaken for silver by Spanish explorers in South America who were looking for gold. Platinum is often used to set higher-quality diamonds because the white metal does not affect the color of the diamond, which may pick up the color in gold.

It is also very strong and holds a stone very securely. Platinum has a number of other attributes.

Platinum is usually 90 to 95 percent pure, making it hypoallergenic. If the product is 95 percent pure, it can be stamped 950PT, 950, PLAT or PLATINUM. If it is 90 percent pure, it can be stamped 900PT. Platinum is a naturally white metal, so it stays white and does not require rhodium (a metal from the platinum family) plating to make it white.

When platinum is scratched, the material is displaced rather than chipped away, making it very durable. Platinum has a very high density, giving it a substantial, luxurious feeling.

Gold

Warm and rich, gold has been prized throughout history. Gold is a soft, malleable yellow metal that can be wrought in many ways. Pure 24-karat gold is generally not used in jewelry. Instead, it is alloyed — or mixed — with other metals. The alloys make the gold harder and can also change its color.

Here are some basics to know about gold:

  • 24-karat gold is pure gold, nothing is mixed with it.
  • 22-karat gold is 92 percent gold. It is still soft and has a very deep yellow color.
  • 18-karat gold is 75 percent gold. It is more durable and is generally used in higher-end jewelry.
  • 14-karat gold is 58.30 percent gold and is frequently used in jewelry.

How does gold turn from yellow to white or to pink? The color changes when different metals are added to the gold. To turn yellow gold into white gold, it is alloyed with palladium — a metal from the platinum family — silver or nickel. Generally, white gold is plated in rhodium, a white metal in the platinum group. It is the rhodium that makes the white gold bright and shiny; without rhodium, white gold is a creamy color. Yellow gold becomes pink when copper is added to the mix.