MUSCAT, DEC 8 – The Ministry of Commerce and Industry (MoCI) said that the precious stone testing laboratory played a major role in the examination and analysis of different types of stones which it receives from citizens, residents or companies which import them. One of these stones is the spinel stone, also called ‘Prince of Sapphire’.
Muna bint Safar al Baloshiah, precious stones inspection expert at the Directorate General of Standards and Metrology, said that the spinel stone was extracted from the mines of Myanmar, Sri Lanka, Tanzania and Tajikistan.
It is known for its hardness and durability. She said: “The spinel is a gemstone and can be installed and used in all jewellery. It is known for its hardness force 8 in the scale of hardness. The spinel stone comes in a variety of colours. But the red, blue and violet colour spinel have more commercial value.”
She said that the spinel which does not contain any visible impurities is more valuable than the spinel stone with impurities of which can be seen with the naked eye. The more impurities are visible, the less valuable the spinel would be.
Muna al Baloshiah urged consumers who want to purchase the spinel stone to test this type of stone in the precious stone testing laboratory of the Directorate General of Standards and Metrology and get a certificate of specification of stone issued determining the type of treatment if there is any.
Muna al Baloshiah also said: Some of the spinel stones undergo heat treatment to change colour. This treatment lasts long if the stone is worn in normal conditions or with any transparent gemstone. Sometimes, certain treatments are done to fill the cracks in the spinel stone to improve its look and appearance. But some materials used for filling of cracks change over time, affecting its appearance.