Frequently Asked Questions
1) Which all gemstones form the Navratnas?
1) Diamond (Vajram)
2) Ruby (Manikyam)
3) Sapphire (Indraneelam)
4) Yellow Sapphire (Manjapushyaragam)
5) Chrysoberyl cat's eye (Vaiduryam)
6) Emerald (Marathakam)
7) Hessonite Garnet (Gomedakam)
8) Pearl (Muthu)
9) Red Coral (Pavizham)
2) What is American diamond?
American Diamond is a man made material called Synthetic Cubic Zirconia with a chemical composition ZrO2 (Zirconium oxide). It is commonly used as a diamond simulant. Its dispersion value is higher than that of diamond. It can be easily distinguished from diamond.
3) What are the factors that can affect the prices of natural gemstones?
1) Colour
2) Clarity
3) Cutting style
4) Carat weight or stone size
5) Treatments done on the stone
6) Distinctness of Phenomena (chatoyancy, aventurescence, asterism, change of colour etc.)
7) Place of origin
4) What are synthetic gemstones? What are the commonly encountered synthetic stones?
Synthetic gemstones correspond to their naturally occurring counterparts in crystal structure, physical, chemical and optical properties. Usually natural stones are distinguished from synthetic stones with the help of inclusions present. Some of the stones that are synthetically produced are:
Synthetic Emerald, Synthetic Chrysoberyl, Synthetic Beryl (red, yellow, blue)
Synthetic Ruby, Synthetic Alexandrite, Synthetic Quartz (purple, yellow)
Synthetic Sapphire, Synthetic Diamond, Synthetic Spinel
Synthetic Opal
Stones like Lapis Lazuli, Turquoise, Coral and Jade are also artificially produced.
5) What are the misnomers/trade names used by gem traders?
Sometimes traders sell a gem under a misleading name usually to make it seem more valuable. Some such misnomers are given below:
6) What are the common synthetic gemstones encountered in the Mineralogy and Gem Testing Lab of the department?
Synthetic ruby , Synthetic sapphire, Synthetic spinel, Synthetic cubic zirconia and Synthetic Yellow Sapphire
Synthetic ruby Synthetic sapphire Synthetic spinel
Synthetic cubic zirconia Synthetic Yellow Sapphire
7) What is Nagamanikya?
Nagamanikya (stone obtained from or guarded by snake) is a myth; found only in Indian mythology. The existence of such a stone is just a story spread around by fraudulent people. No standard gemmology text books refer to such a stone.
8) What are the common gemstones found in Kerala?
Kerala does not occupy a prominent place in the gemstone deposit map of India. Meagre deposits of good quality chrysoberyl cat's eye and alexandrite occur in the southern districts of the state. Sporadic occurrences of ruby, sapphire, topaz and aquamarine have been reported.