Andalusite Facts and Buying Guide
by Sheweta Dhanuka
This versatile gemstone strongly exhibits pleochroism. In this phenomenon, when different light rays fall on the gemstone it displays different colours in different directions/facets. The extraordinary pleochroism occurs naturally in this gemstone but it is largely dependent on the orientation of the gemstone. The orientation of the crystal can be enhanced through efficient cutting.
There by the article written below provides the necessary information and knowledge about this semi precious stone, which would assist the buyer in buying the true gem. The best way to learn about any gemstone is to begin with four important Cs and then other properties. In this way the buyer can acquire all the required details. Hence, we start with the colour.
This versatile gemstone strongly exhibits Pleochroism. In this phenomenon, when different light rays fall on the gemstone it displays different colours in different directions/facets. The extraordinary Pleochroism occurs naturally in this gemstone but it is largely dependent on the orientation of the gemstone. The orientation of the crystal can be enhanced through efficient cutting.
It is found in many colours and shades similar to earth tones. Brown and green are the main colours that occur in different shades like reddish brown, greenish brown, reddish green, yellowish green or orangey brown. However other colours are red, gray, orange and pink. The pleochroic colours are red, green and yellow. Through the phenomenon of Pleochroism the originality of the gem can be known.
This gemstone may or may not have inclusions. In few stones no inclusions are visible while other stones possesses few dark inclusions. Some stones would consist of elongated fractures that appear due to the intersection of good cleavages/partings within its structure. The transparency of the stone decreases with the increase of inclusions in the stone. A gemstone without any flaws would be completely transparent and it would turn translucent to opaque when the amount of flaws increases.
Cutting is the most crucial aspect in case of this amazing stone. The entire beauty of the gemstone is dependent solely on the cutting. Cutters have to efficiently cut the stone in such a way that the phenomenon of Pleochroism is highlighted and the cut shape display a blend of pleasing colours. And also the inclusions should be minimized.
Fancy and innovative shapes offer captivating colour play in the same stone. Pear, round, cushion, emerald, oval and many more shapes are available in the market. Each shape has its own uniqueness. Round and rectangular cushion cut are the best shapes that display the perfect blend of the colours. While when the rough is cut along the length in oval, marquis and emerald shapes it shows two different colours that is lighter colour shade in center and darker shade in the outer corner of the gem. The colours come out very beautiful and soothing to eyes if given proper cut. In fact it becomes difficult to take the vision away from the stones. Genuine stone would exhibit beautiful colour blend or different colour shades when seen in different directions.
It occurs mostly under 5 carats weight. Gems between 5-10 carat weight are found in very few mines while more than 10 carat is almost rare and is produced once in many years.
This semi precious gemstone is priced fairly well for every range in spite of having rare occurrence. Price is determined by the carat weight, cut, colour display and clarity. Origin of the stone does not affect the price much. If the gem is given a custom cut as desired by the buyer then the price would certainly increase. The gemstone possessing large carat weight, clarity and perfect cut that display natural blend of colours is most expensive. Gems without flaws are valuable. Stones with poor cut and artificially polish looks totally unattractive thus are priced least. Enhanced stones would also cost less.
The prime producer of this gemstone are Brazil and Sri Lanka. It is also mined at UK, Spain, Australia, United States, India, Russia and China. It is found in metamorphosis and sedimentary rocks under the high pressure and temperature. Also in granites and pegmatites that arwwe rich in aluminum and silica. There are three polymorphs of Aluminum Silicate viz. kyanite, sillimanite and Andalusite. All three are related to each other with respect to their pressure and temperature formation. These are found rarely and produced in limited quantity even when so many countries produce it.
Enhancement and Imitations
Andalusite is seldom enhanced or heat-treated. Only in few countries it is enhanced to improve the colour displays in order to augment the cost of the gem. It is not very popular among the gemstone buyers therefore noticeable numbers of imitations are not been traced. However, it is sold under many trade names to mislead the buyers.
Its unique colour display and hardness makes it the desired choice for the men’s jewelry. It is even widely used for the female jewelries. It is very well paired with other gemstones like diamonds, topaz, citrine, pearls etc. The rings holding this gemstone along with diamonds are so exquisite that every woman would like to buy at least one. As it occurs in small carat weight, one single ring can hold 1-5 stones having the total weight between 1-4 carats. Sometimes weight of the stone can be less than one as well like one stone of 0.78 ctw, two stone of total 0.55 ctw or four stones of 0.65 ctw etc. For men’s rings higher ctw stone is preferred that is between 2-4.
Like rings, stud earrings paired with diamonds are very attractive. Earrings and pendants can hold any carat weight between 1-4 ctw. It all varies from one design to another and also with the size of the stone in terms of carat weight. All the jewelries can be made up of 10K, 14K or 18K yellow gold, sterling silver and sometimes even with white gold. Prong setting is quite common for the rings and stud earrings jewelry. Hence, buyer should ensure that prongs hold the stones very well.
Beads are also available in all shapes and styles. These are mostly used for making necklaces and bracelets. Other than the jewelries it is used as the mineral specimen.
This gemstone is relatively a tough stone having the hardness between 6.5-7.5 Mohs. This is the reason why it is preferred more for the men’s jewelry. It does not require constant care but few general gemstone precautions are the necessary for the lifetime retention. The Pleochroism phenomenon can be affected if it exposed too much to the acidic solutions. The stone can be split with the direct blows or too much of rough handling. Therefore, exposure to harmful chemicals should be avoided and general protections should be implemented.
Andalusite is one of the most beautiful creations of the nature. The different colour display in different directions is absolutely magnificent. Still this beauty is untouched in many parts of the world. It can certainly create waves in the jewelry business once it gains little attentions and popularity among the jewelry lovers!!