Topaz

Topaz is a hard, transparent gem found in many colors. The one most seen in jewelry is blue topaz, almost always treated from colorless topaz.

Properties #

• Composition: aluminum silicate with fluorine.
• Hardness: 8 on the Mohs scale, but with perfect cleavage: it chips with a knock.
• Color: colorless, blue, yellow, pink, orange (imperial topaz) and others.
• Origins: Brazil, Russia, Nigeria, Sri Lanka and the US.
• Treatments: blue topaz is almost always made by irradiation and heat.

Uses in jewelry #

• Rings, earrings and pendants.
• November jewelry (birthstone, together with citrine).

Pros and cons #

Advantages #

• Brilliant and transparent.
• Widely available and affordable (blue).
• Many colors.

Limitations #

• Its cleavage means it chips on impact.
• Blue is almost always treated.
• Some colors (imperial) are expensive.

Care and cleaning #

• Avoid knocks and sudden temperature changes.
• Clean with lukewarm water and a soft brush.
• Do not use ultrasonic on pieces with fractures.

See also #

• Quartz and its varieties
• Birthstones by month