Tanzanite: Lavish, Elegant, Fashionable . . .

Penelope Gilliver, Cataloguer from the Jewellery Department at Fellows, has been researching tanzanite ahead of Fellows’ auction of Gemstones, which ends on Friday 29th May.

Sourced from only one location, the Merelani Hills of Tanzania, tanzanite in its finest form is a highly sought-after precious gem, with a luxurious range of hues, rivalling the beauty of similarly coloured stones, such as sapphire. With strong pleochroism, meaning the gemstone can show different colours when viewed at different directions in the crystal, it can be cut to show rich blue-purple hues, or more delicate violet hues; the scope of colours is fantastic. The pleochroism is usually visible to the unaided eye, and is a fascinating and pleasing feature to see in this gemstone.

Tanzanite is relatively new in the world of gemstones, only being discovered in 1967. The luxury jeweller Tiffany & Co gave this gemstone its name, and realising its potential for desirability, launched its popularity in 1968 with a publicity campaign. Due to tanzanite being available from just one country, this produced an instant element of rarity to the gemstone, so you can feel certain you have a valuable and special stone in your life.

Tanzanite is a popular gemstone to be used in jewellery. Whether it be the rich and vivid colours, or the soft and elegant violet hues of this gemstone, it is a beautiful stone to have as a part of your jewellery or loose gem collections. With a hardness of 6 to 7 on the Mohs scale of hardness, tanzanite has a fairly good durability, and is stable enough to be used in jewellery; it is always advised to be cautious and avoid wearing your tanzanite when handling cleaning chemicals, or conducting activities in which your jewellery can be knocked and scratched. All you need to use to clean your tanzanite is some soapy water, this is sufficient enough to keep them looking sparkling and bright.

“Some specimens, like any other in the commercial gemstone world, are given a helping hand with their colour, to produce the more desirable blue and violet hues. You don’t need to be disheartened by this fact, these basic treatments just mean you can see the full potential of the beautiful colours that are possible from these gemstones!”

Penelope Gilliver, from Fellows’ Jewellery Department

Some facts about tanzanite:

• Typically forms as a prismatic crystal
• A tanzanite crystal will have striations on some crystal faces
• Naturally found as violet-blue and purple hues
• Zoisite is the gemstone family tanzanite belongs to
• A selection of gemstones tanzanite could be confused with are iolite, sapphire, blue spinel
• Named by Tiffany & Co
• Indication of heat treatment would be if there are only two pleochroic colours, blue and violet
• Tanzania is the home of Tanzanite
• Examples that are large in size are more rare