Nephrite is slightly softer that jadeite and is often veined.Ī document, issued by an Observatory or an official ratings bureau, that certifies the quality of a watch which has proven, in trials, to meet with a given standard. Labradorite has a hardness of 6 to 6.5 and a specific.Ī small diamond that weighs under 1/5 carat or 0.20 carat.Ī family of the jade group of ornamental gemstones. Invented by Bonnicksen, a Danish watchmaker established in London.See complication.Ī variety of plagioclase feldspar that has a greyish background with flashes of colour called labradorescence. Nephrite, the more ancient.Ī device similar to the tourbillon, the difference being that the cage is driven by the third wheel. Jadeite is the variety that ranges in colour from green to white to lilac to brown to almost black.

Jade is a gem group with jadeite and nephrite as the two varieties. Enamel is used to decorate metal surfaces, in particular gold.Ī craftsman who produces decorative objects in precious metals, as well as in pewter and copper.Ī metal part that strikes gongs causing them to vibrate and produce sound.ĭiamonds that have been exposed to radiation in order to change their colour from yellowish to fancy yellow or blue.

In a watch case, the cover, transparent or not, opposite the dial.Ĭubic zirconium (also known as cubic zirconia) is an artificial, lab-produced diamond imitation.Ī valuable yellowish green, very lustrous and rare variety of the garnet group.Ī vitreous substance whose main component is silica mixed with oxides (transition metals) that create a vast palette of colours. The hour numerals or decorations that are cut from sheets of metal then affixed to the dial.

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