Topaz is an aluminum silicate that contains fluorine and hydroxyl. It is the hardest naturally occurring silicate mineral. In its natural state, it is a golden brown to yellow. A variety of impurities and treatments may make topaz wine red, reddish-orange, pale green, or pink. Topaz in itspure form it is colorless

Topaz identification

Topaz can be distinguished by its Mohs hardness of 8 rating. It can be told apart from aquamarine by its orthorhombic crystal structure. Topaz can also be differentiated from chrysoberyl by its lower density and different chemical composition and it also shows some weak fluorescence.

Topaz Deposits

Brazil is one of the largest producers of topaz. Some important deposits are found in Afghanistan, Australia, Myanmar, China, Germany, Japan, Madagascar, Mexico, Namibia, Nigeria, Pakistan, Russia, Zimbabwe, Sri Lanka, Ukraine and USA. Natural light-blue topaz is found in Northern Ireland and the UK.

Topaz Hue

Topaz ranges from colorless to yellow, orange, red-brown, light to dark-blue, pink to red, violet and light-green.Impurities and treatments gives topaz its different colors.The most rare and precious topaz is yellow, or pink to reddish orange, and is known as "imperial topaz". The pink and red varieties come from chromium replacing aluminum in its crystalline structure.

Topaz Clarity and Surface

Topaz is transparent to translucent. It exhibits eye-clean clarity with few inclusions. Topaz is highly prized for its brilliance and vitreous luster.

Topaz Cut and Shape

Topaz crystals are usually elongated or columnar,therefore, they’re often cut as long oval or pear shapes. All the standard gem shapes such as ovals, pears, rounds, cushions, triangles, marquise, and emerald cuts as well as designer shapes are available.

Topaz care and cleaning

• It has Mohs hardness of 8 rating, which makes it durable and hence it does not scratch easily.
• However it has perfect cleavage, meaning, the force of a single blow could cause it to split.
• Use soapy water and a soft cloth to your Topaz. Be sure to rinse well to remove soapy residue.
• To avoid scratches, store topaz away from other gemstones.
• Remove Topaz jewelry before exercising, cleaning or engaging in harsh physical activities.

Topaz Gemological Properties

Chemical Formula: Al2SiO4(F,OH)2 Fluor containing aluminum silicate

Crystal Structure: Orthorhombic, prisms with multi-faceted ends, often octagonal in cross-section

Color: Colorless, yellow, orange, red-brown, light to dark blue, pink-red, red, violet, light green

Hardness: 8 on the Mohs scale

Refractive Index: 1.609 - 1.643

Density: 3.49 - 3.57

Cleavage: Perfect

Transparency: Transparent and translucent

Double Refraction : 0.008 to 0.016

Luster: Vitreous

Fluorescence: Under long wavelength UV, white and blue shows a weak yellow or greenish glow; brown, pink and yellow can show a strong orangeyellow glow; red shows a weak yellow-brown glow