Zilberschmuck

Don Stuart and I at the opening reception of his exhibition, 50 Years of Creative Excellence, and what excellence it is! The room is filled with such beautiful work, what a talented man, so glad to see the show. The exhibition is at the Art Gallery of Northumberland, Victoria Hall, 55 King St West, Cobourg, ON. Open until 4:00 pm daily except closed on Mondays, show continues to October 29th. A must see!

Misinterpretation, Misunderstanding and Mistakes Understand Incorrectly This article is regarding what you thought ‘it’ meant, because that is what you were lead to believe. Over the years I have heard many stories about jewellery and it occurred to me that some are inaccurate, misleading, or just plain incorrect, and I would like to talk about things that have been misunderstood and misinterpreted, but I’m not including any of the deliberate deception that some people do t...Continue reading

New jewellery store opened in the east end at 1015 Queen Street, just east of Pape. I'm working today noon to 5:00. Come out and see us. https://www.facebook.com/ontheotherhandjewellery/

Plagioclase feldspar - labradorite Everyone loves the pretty flash of colour from labradorite. It always reminds me of the iridescent Costa Rican, Morpho butterfly, as it flutters along a forest riverside. While I’ve never been to Costa Rica, I have seen the beautiful butterfly in a conservatory and visualizing a forest is far more romantic to me then a greenhouse, so I’m going to use that image. So what is labradorite and where does it come from? In 1770, a missionary on an... island off the coast of Labrador, Newfoundland, first discovered this pretty flashy feldspar and named it after the region it was found, and while many people think that Newfoundland is the only source for labradorite, it can be found in many places in North and South America and Norway, but the best quality pieces come from Finland and Madagascar. The Finland variety, has the gem trade name Spectrolite, and is the most prized labradorite of all for its spectral colours. Labradorite belongs to the group called feldspar, (in gemology, a group is composed of a number of closely related species like feldspar and garnet) and feldspar is the most widespread mineral on earth, and includes the gemstones Labradorite, Sunstone and Moonstone. There are two basic groups of feldspars, and all of them contain aluminum, oxygen and silicon and with the addition of other elements this creates the different feldspar, those that contain potassium, and those that contain calcium and sodium. Plagioclase feldspar contains a mixture of sodium and calcium and these include labradorite, the focus of this article. What is the colourful flash called and what causes it? Labradorite displays labradorescence, which is the broad flash of colour that appears and disappears when the gem is moved; most often, it is just a plain looking dark greyish stone, but when it shows the phenomenal colours the feldspar becomes the gemstone labradorite (Fig. 1). The phenomenal colours are caused by interference of light reflecting off the gem’s layered structure. The triclinic crystal structure, which labradorite belongs to, have three leaning angles, none are at right angles, and all of the axes are of varied lengths. In the case of labradorite, layers of albite are intergrown with plagioclase feldspar in fine layers and when light hits these microscopic layers, its wavelengths shift. The wavelengths interfere with each other making parallel bands of shimmering spectral colour; typically blues and greens called labradorescence, but can contain other colours (Fig. 2). Feldspar are softer gems with cleavage in two directions, so they require protective settings and I would not recommend it in a ring or bracelet if you are hard on your jewellery, but a pair of earrings or a necklace of labradorite will bring you years of enjoyment. Sources Gemological Institute of America, Coloured Stones course materials 2015.