Topaz is a wonderful semi-precious stone, the birthstone of November, and blue topaz is the birthstone of December. Each type of topaz has an anniversary that it represents; Meaning that blue topaz represents the fourth anniversary, while imperial topaz represents the twenty-third anniversary. Topaz is one of the strongest silicate minerals, and one of the hardest minerals in nature (how is topaz formed). It is a very popular stone in jewelry field. In the past, this stone was closely associated with the color yellow, and all yellow-golden stones were called topaz. Natural is called “precious and imperial topaz”, while imperial topaz is a pinkish shade of topaz that was discovered in Russia in the 19th century. Imperial topaz is now extracted from the topaz mines in Minas Gerais, Brazil.
Ways and means of distinguishing natural topaz stone
The birthplace of topaz gemstones in the cut-offs in zones of refraction is where the most special and unusual gemstones for us can be found. Therefore, it is necessary to take care of those stones and conduct some tests for them to distinguish them. In addition, it is necessary to know the difference between topaz and other stones; As the properties of glass are very similar to topaz, although it does not have double refractive indexes.
Undoubtedly, tourmaline is one of the most frequently confused stones with topaz when doing By tests, tourmaline has refractive indices that range within the range of indexes that topaz has but are sufficiently higher than those of topaz making it easy to distinguish between the two.
They can also be easily differentiated by measuring the degree of density
. As the tourmaline stone floats while the topaz stone is dipped in water.
You can also examine the topaz stones to distinguish them through the use of a microscope and note their structure.
As for the glass pieces It is difficult to distinguish them from topaz stones, but with the presence of modern equipment and new machines, it is possible to distinguish between them by Use of the polariser
There are other rare gemstones similar to topaz such as danburite and andalusite. and apatite. And
all these stones float in methylene iodide, while topaz is dipped in it the stones The three. In addition, there is apatite and it also overlaps with topaz but it can be distinguished from it because Apatite is a monolithic stone the hub. If the test stone is attached to a stand, news readings may be required
using a monochromatic light source Light through a lamp or filter
Danburite also shows indicators up to 1.630 and 1.636 and both indicators differ from the midpoint of the stone (beta indicator) in 1.633. As for the colorless topaz stone, it shows indicators up to 1. 633 – 1.
, but yellow topaz indices reach 1.629- 1. 637. However, the midpoint (beta indicator) is 0. from a low reading, and therefore the low reading is relatively constant.
The stones that overlap with topaz are not restricted to those named, as topaz and peridot are frequently misidentified. Both stones are sometimes confused merely because their refractive indices are roughly two units of separate line 1. 58 on the refractive indices scale. When reading the signs, it is simple for a person to make a mistake, especially if he is in a rush. He may interpret the topaz indicators (1).62) as aquamarine indications (1.60 ). This occurs when the inexperienced individual doing the test looks at the topaz stone and believes it is peridot, causing its signs to drop and become equal to the indicators of aquamarine (1.637 ).
The properties of topaz play an important role in distinguishing it from other stones; Where it represents the liquid to a large extent and the gas that fills the cavities that contain two immiscible liquids, in which gas bubbles appear that accompany the liquid and that have