Using the
most sophisticated electron microscope techniques available, we have
gained a better understanding of what happens at the surface of the
Argentium Silver... find out more here: argentiumguild.blogspot.com/p/monthly-feature
Friday, 27 January 2012
Bangkok Gems & Jewelry Fair 2012
Legor Group will be promoting Argentium Silver at the Bangkok Gems & Jewelry Fair, 9-13 Feb 2012 - Stand XX44,46 (Hall 3)
Impact Challenger
Bangkok, Thailand
Monday, 23 January 2012
Argentium at T-Gold 2012
This year's Argentium wall design at T-Gold, Vicenza Fair 2012, in association with Legor Group.
Rio In Motion
Rio In Motion is here! 22-27-Jan 2012
This annual event hosts a week of exciting classes, tours and demos at Rio Grande, including Argentium silver classes by Ronda Coryell on 22 & 23 Jan. For further details please go to: www.rioinmotion.com
Rio Grande, Albuquerque, New Mexico, USA
Monday, 9 January 2012
Interview with Cynthia Eid
If you are a Member of the Guild, please feel free to post your questions for Cynthia on our facebook wall: http://www.facebook.com/ArgentiumSilver or email questions to: info@argentiumguild.com
Please could all questions be submitted by Friday 13th January.
Thursday, 5 January 2012
Jewelry Technology Forum
The Jewelry Technology Forum is a highly successful symposium in terms of both participation and content. JTF is the place to obtain information on the latest developments and trends in jewelry production. The 2012 seminar will feature two important themes: colour and the new selective laser melting technology, a potential revolution for jewelry production.
Click on the link below for a list of key speakers and further information on Legor Group's website... http://www.legor.com/index.php?pagina=pagina_generica.php&id=431
Featured Guild Members for Jan 12
We are delighted that Birgit Kaler and Patricia Tschetter are Featured Argentium Guild Members for January 12. You can find out more about them and see some of their work here... http://www.argentiumguild.com/#!__featured-members
Tarnish Resistance and its Measurement.
So, what is tarnish? Simply, it is a dark discoloration on the surface of silver items predominantly caused by their exposure and reaction with sulphur present in the air (as pollution) in compounds such as sulphur dioxide or hydrogen sulphide. The rate at which tarnish occurs is also influenced by higher ambient temperatures or higher humidity levels.
I have written previously (Blog Post, 22nd March 2011, Different Silver Alloys) about the different types of silver alloys available. Some of these other silver alloys also claim improved tarnish resistance, so in this article I want to discuss how to test silver alloys to best assess their relative tarnish resistance.
The most important thing to say about tarnish testing is that no individual test can match the complexity of the real-life conditions to which a silver item will be subjected. The temperature, light intensity and levels of pollution vary room by room and location by location, so any meaningful testing of tarnish resistance needs to consider the different factors which influence this reaction.
Generally the silver industry considers only one aspect of tarnish resistance that of sulphur attack in assessing its tarnish resistant alloys. The Argentium approach is more demanding and we require alloys to pass three different tests before they are considered tarnish resistant, these are:
Sulphur test - This test is based on a standardised corrosion testing procedure (ISO 4538) used within the precious metals industry which utilises a chemical called thioacetamide to reproduce the effects of sulphur and sulphurous gases found in the atmosphere and everyday substances.
Perspiration (sweat) test – This test reproduces the effects of perspiration and skin contact with silver alloys and is based on a standardised procedure (ISO 12870) used in the spectacles industry to asses the perspiration resistance of spectacle frames when in contact with an artificial sweat solution.
Ultraviolet light test – This test determines whether alloys are photosensitive to ultraviolet light, this is especially applicable to silver articles that are on display and exposed to sunlight. Ultraviolet light is known to influence the creation of ozone (specifically light at a wavelength of 185nm); ozone can be considered an ‘active oxygen’ molecule which can act greatly increase the rate of tarnish of a silver alloy
To standardise the tests pieces of a regular sterling alloy are always included to provide a base reference sample and to quantify the testing the assessment of the alloys tarnish resistance is carried out by colour measurements using the CIELab system (Blog Post, 5th September 2011, How Silver is Silver?).
Argentium silver alloys are required to demonstrate superior tarnish resistance in all of these tests and in future posts I will explore how the colour measurement data from the CIELab testing can be used to assess the relative tarnish resistance of the different types of silver alloy.
I have written previously (Blog Post, 22nd March 2011, Different Silver Alloys) about the different types of silver alloys available. Some of these other silver alloys also claim improved tarnish resistance, so in this article I want to discuss how to test silver alloys to best assess their relative tarnish resistance.
The most important thing to say about tarnish testing is that no individual test can match the complexity of the real-life conditions to which a silver item will be subjected. The temperature, light intensity and levels of pollution vary room by room and location by location, so any meaningful testing of tarnish resistance needs to consider the different factors which influence this reaction.
Generally the silver industry considers only one aspect of tarnish resistance that of sulphur attack in assessing its tarnish resistant alloys. The Argentium approach is more demanding and we require alloys to pass three different tests before they are considered tarnish resistant, these are:
Sulphur test - This test is based on a standardised corrosion testing procedure (ISO 4538) used within the precious metals industry which utilises a chemical called thioacetamide to reproduce the effects of sulphur and sulphurous gases found in the atmosphere and everyday substances.
Perspiration (sweat) test – This test reproduces the effects of perspiration and skin contact with silver alloys and is based on a standardised procedure (ISO 12870) used in the spectacles industry to asses the perspiration resistance of spectacle frames when in contact with an artificial sweat solution.
Ultraviolet light test – This test determines whether alloys are photosensitive to ultraviolet light, this is especially applicable to silver articles that are on display and exposed to sunlight. Ultraviolet light is known to influence the creation of ozone (specifically light at a wavelength of 185nm); ozone can be considered an ‘active oxygen’ molecule which can act greatly increase the rate of tarnish of a silver alloy
To standardise the tests pieces of a regular sterling alloy are always included to provide a base reference sample and to quantify the testing the assessment of the alloys tarnish resistance is carried out by colour measurements using the CIELab system (Blog Post, 5th September 2011, How Silver is Silver?).
Argentium silver alloys are required to demonstrate superior tarnish resistance in all of these tests and in future posts I will explore how the colour measurement data from the CIELab testing can be used to assess the relative tarnish resistance of the different types of silver alloy.
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