×

Topaz - Mineral

Top
Download PDF
FAQ

What is Topaz?

Bookmark added to your notes.
View Notes
×

Topaz mineral is an aluminium and fluorine silicate with the chemical formula  Al2SiO4(F, OH)2. It is used as a gemstone in jewellery and other decorative materials. The topaz in its natural state has a golden yellow colour. Various impurities and treatment can make topaz wine red, pale grey, reddish-orange, green, pink, or opaque.


[Image will be uploaded soon]


Topaz Crystal on white matrix


Topaz meaning - Topaz is a silicate mineral. It is one of the hardest natural minerals to have a low recovery rate and  It is produced in many parts of the world. The name topaz is derived from the Greek words Τοpáziοs or Τοpáziοn.

Topaz meaning - In the Bible, Topaz is described as a “stone of fire,” and is highlighted as one of the gems laid in the foundations of the walls of the holy city Jerusalem.


Composition of Topaz 

What is Topaz made of?  A natural Topaz stone is composed of rare silicate mineral, with the composition of  Al2SiO4(F, OH)2 it is usually formed in the cavities and crevices of rhyolite, pegmatite, and some of the other igneous rocks. The gemstones are mined from numerous places of the world and the natural stones look golden brown or yellowish in colour.   


Topaz Colours 

You can find different colours of topaz which includes red, grey, orange, blue, blue colour  (we will look at the blue topaz in detail later), pink and purple. These colours are made from impurities or man-made treatments that change the colour of natural gemstones.


First Discovery of Topaz

The first yellow crystals (modern topaz) were discovered in Germany in 1737, and in 1740, a large gemstone was discovered in Brazil. However, it seems to be mixed in line with the topaz.

 The large stone was initially believed to be a diamond and was quickly fixed in place of the Portuguese crown. The gem was later identified as a topaz rather than a diamond - but it retained its place over the royal attire regardless.


Modern-Day Topaz Mining Deposits

Nowadays, topaz is found in many places around the world, including Pakistan, Afghanistan, Japan, Mexico, Madagascar, Burma, Australia and the USA. A large number of topaz rock crystals have been found earlier in Ukraine and Brazil.


What are Topaz Characteristics?

Topaz, in its natural state, is golden brown to yellow - a feature that will be confused with the citrine sometimes, a less important gemstone. The specific gravity of all topaz shades is much heavier than the citrine (about 25% per volume) and this weight difference can be used to separate two stones of equal volume. Also, if the volume of a given stone can be determined, its topaz weight can be established and tested on a critical scale. Similarly, glass stones are much lighter than topaz.

A variety of impurities and treatments can make topaz wine red, light grey, reddish-orange, light green, or pink (unusual), as it does not look good. The pink and red varieties are derived from chromium instead of aluminium in their crystalline structure. The colour of an Imperial topaz is yellow, pink (rare, if natural) or pink-orange. The topaz of the Brazilian state is usually bright yellow to a deep brown hue, sometimes violet. Many brown or pale topaz are treated to turn yellow, gold, pink, or violet. Some of the topaz of the empire may fade when they are exposed to the sun for a long time. The naturally occurring blue topaz is rare. Normally, colourless, grey, or pale yellow and blue material are treated with heat and radiation to produce the desired blue colour. Mystic topaz is a colourless topaz coated with a coating of smoke that gives the rainbow effect to its surface.

Although very hard, topaz must be treated with greater care than other minerals of similar hardness (such as corundum) due to the weak bonding of atoms of stone molecules and one or another axial plane. This gives the topaz a tendency to pierce such a plane when struck with sufficient force. Topaz has a low index of refraction compared to a gemstone. Therefore, stones with large features or tables are not as smooth as in mineral-cut stones with high refractive indices, although the top quality colour palette is shiny and shows more "strength" than similar cut quartz. When given a typical "glittering" cut, the topaz may indicate a feature of a glittering table surrounded by the sides of a dead-looking crown or a ring of glittering crown elements with a dull table that is exactly the same.


Do You Know?

How is topaz made? In nature, Topaz is often colourless and some of them come in many colours, but the colourless variety of the topaz often creates confusion with diamonds.

For Topaz to form, you need a high level of fluorine, which is formed and broken or in caves. The hot liquid (like mud) will break through the Fluorine and pull into the cracks between the rocks. There, Topaz is made from depleted fluorine. Like diamonds (and many gemstones), Topaz needs some of the harshest areas to form and further it will be pushed to the surface over time.

FAQ (Frequently Asked Questions)

1. How is Topaz(Lab Blue Colour) Made? 

Answer. Blue topaz is created from colourless or very lightly coloured topaz. The topaz is irradiated and heat-treated to bring out the blue colour and the experts apply different levels of radiation to create various shades of blue.

2. How is Topaz Valued?

Answer. The price of topaz has fluctuated over the years. Value is important based on certain factors. The colour of the gem plays a key role in determining the value of topaz. Common pink and red stones are considered high values, followed closely by orange and yellow. Orange and brownstones are often considered the most common. In the family of blue topaz, the London Blue Topaz is considered to be the most valuable and desirable. London Blue has a blue hue with a hint of green or grey in the middle.