What is red and white gold?

Pure gold (24 carat) is soft and can not used to make jewels. In India, it is normally 22 carat and in Europe it is 14 carat and very rarely 18 carat.

It is always the metal in the alloy that makes the colour different.

Normally copper, silver and other base metals form the gold alloy.

• Copper is the most common metal and it forms a red alloy.
• 25% copper in the antique created a rose gold.
• Iron alloys with gold gives blue gold.
• Aluminium and gold give purple gold alloy.
• 14 carat and 18carat with silver give a greenish yellow gold.
• The white gold alloy is made with palladium or nickel.

This is the story of gold colours.

What is catalytic converter?

A special filter in a car engine used to lower the exhaust pollution level; it can break down many exhaust pollutants.

The catalytic converters are used to reduce the amount of carbon dioxide, carbon monoxide, hydrocarbons and nitrogen oxide. Platinum, palladium and rhodium are used in catalytic converters. Chemical reaction and temperature makes these emission substances to carbon and nitrogen. The emissions are also reduced significantly.

The other problem produced here is the poisonous heavy metal platinum or palladium will be released into the environment.

The fine carbon particles are also dangerous to our health.