Back to gem encyclopedia


Honey yellow. Fiery orange. Cyclamen pink. Icy blue. In warm or cool tones, topaz is a lustrous and brilliant gem.

Responsive image
Reddish Pleochroism

Topaz’s reddish pleochroic color often appears at the ends of cut gems.

Responsive image
Prized Color

Rich reddish orange is one of this gem's most coveted colors.

Responsive image
Long Oval

Because topaz crystals are typically elongated, polished gems are often cut long.

Responsive image
Responsive image
Columnar Crystal

This topaz crystal has a columnar prism with a “chisel-like” termination.

Responsive image
Basal Cleavage

Parallel to the base of the crystal are weaker bonds between the atoms.

Responsive image

The color the trade calls imperial topaz is highly prized and very rare.

Responsive image


About Topaz

about topaz

Topaz actually has an exceptionally wide color range that, besides brown, includes various tones and saturations of blue, green, yellow, orange, red, pink, and purple. Colorless topaz is plentiful, and is often treated to give it a blue color. Topaz is also pleochroic, meaning that the gem can show different colors in different crystal directions.

Topaz Description

Topaz History and Lore

Topaz Journey

Birthstones & Anniversaries

Precious topaz is a birthstone for November and blue topaz is a birthstone for December. Blue topaz is the gem of the 4th anniversary and Imperial topaz is the gem of the 23rd anniversary.


The royal court in Portugal celebrates the discovery of Imperial topaz in 1768.

271 kilos

A transparent topaz crystal discovered in Minas Gerais, Brazil weighs an astounding 596 pounds.

10 MeV

Irradiating colorless topaz with electrons at energy of 10 million electron volts creates a sky blue color.


  • Mineral: Topaz
  • Chemistry: Al2(F,OH)2SiO4
  • Color: Yellow, orange, brown, pink to red to purple red, blue , light green and colorless
  • Refractive index: 1.619 to 1.627
  • Birefringence: 0.008 to 0.010
  • Specific gravity: 3.53
  • Mohs Hardness: 8


There are a number of processes used to alter the color, apparent clarity, or improve the durability of gems.

Learn More


Some gemstones have synthetic counterparts that have essentially the same chemical, physical, and optical properties, but are grown by man in a laboratory.

Learn More


Any gem can be imitated—sometimes by manmade materials or by natural materials chosen by man to impersonate a particular gem.

Learn More
gem love

Why We Love This Gemstone


Topaz comes in some of the gem world’s largest crystals: the largest are kilos, not carats.


Faceted topaz takes such a high polish it’s slightly slippery to the touch.


Topaz is pleochroic, displaying different colors in different crystal directions.

Quality Factors

Topaz comes in a variety of colors from shades of blue to the rare reddish imperial colors.


quality factors

The most valued topaz colors are orangy red to red. Blue gems are widely available.


quality factors

Topaz used in jewelry is typically eye clean with no visible inclusions.


quality factors

Topaz crystals are usually columnar, and cut as oval or pear shapes to improve yield.

Carat Weight

quality factors

Topaz often forms as large crystals. These can yield sizable cut gems.

Topaz Quality Factors: The Comprehensive Guide


Explore sources, gemological research, and the role of gems in history.

The Radioactive Decay Pattern of Blue Topaz Treated by Neutron Irradiation

Jian Zhang, Taijin Lu, Manjun Wang, and Hua Chen Read Article

An Update on Imperial Topaz from the Capao Mine, Minas Gerais, Brazil

Daniel A. Sauer, Alice S. Keller and Shane F. McClure , Dec 1, 1996 Read Article

Pink Topaz from Pakistan

Edward Gübelin, Giorgio Graziani and A. H. Kazmi , Sep 1, 1986 Read Article

Topaz, Aquamarine, and Other Beryls from Klein Spitzkoppe, Namibia

Bruce Cairncross, Ian C. Campbell and Jan Marten Huizenga , Jun 1, 1998 Read Article