Goto your account
Search Stories by: 
and/or
 

Gemstones

Articles from GEMSET JEWELLERY (306 Articles)











Understanding gemstone wear and tear

It may seem elementary but knowledge of correct gemstone treatment is essential for new retail staff. IAN DUN discusses types of gemstone damage and how to avoid them.

Just like clothing and footwear, gemstones can show signs of wear and tear after sustained or improper use. Great care is needed in the jewellery workshop because gemstone materials can be affected by many potentially-damaging processes. Natural, synthetic, untreated, treated, organic and composite gemstones are all susceptible to damage if mistreated.

Abrasion, impact, pressure, acids, oils, alkalis, chemical compounds and thermal shocks are typical of the forces that jewellery is designed to withstand to some degree.

Abrasion

Abrasion is the most common force encountered in normal wear and is indicated by a material’s exposure to harder particles on a regular basis. The urban environment has a large amount of grit, grime and dust containing a high proportion of silica. Softer gemstones will show evidence of scratching and dulling if they are worn on active parts of the body like the hands and wrists. Durable gemstones will have a hardness of greater than seven on Mohs Scale.

Quartz minerals and crystals, tourmalines, most garnets, topaz varieties, beryl varieties such as emerald and aquamarine, spinels, chrysoberyl, corundums such as sapphires and rubies, and of course diamonds all have the necessary hardness to withstand abrasion to varying degrees.

Impact and pressure damage

Impact occurs when materials hit things and gemstones such as spinel, garnet and emerald are more susceptible to impact fracturing while softer materials like jadeite, nephrite, and even pearl can withstand regular knocks without major damage due to their molecular structure.

Pressure occurs when sustained force is applied as a result of repeated stress to the piece or when a piece is jammed or accidentally mishandled. The shape of the gemstone’s cut is often more important in resisting damage than hardness. Some relatively soft stones like turquoise and coral are often present in well-worn and misshapen jewellery, worn and scratched but still structurally intact. Hard gemstones cut to sharp and shallow shapes, like pear and marquise cuts, can be damaged by pressure and the corners of princess-cut diamonds fractured by localised pressure.

Chemical damage

Chemical reactions can occur as a result of exposure to materials like liquids and skin oils. While metals are the usual victims of adverse chemical reactions, any gemstone that is porous or absorbent has the potential to be damaged by personal grooming products, cleaning agents, solvents and other household chemicals. Pearl, bone, coral and lapis lazuli can all deteriorate after contact with perfumes or anything acidic.

Thermal shock

As a rule of thumb, if a human’s body can stand the heat then a gemstone can also. For this reason, it’s less likely for gemstones to experience thermal shock while worn but they shouldn’t be stored in any place that is exposed to extreme temperatures.

Luckily, unlike most garments, gemstones accumulating evidence of the wearer’s lifestyle can be valuable for generations. How many pieces of clothing can do that?   











ABOUT THE AUTHOR
Ian Dun

Ian Dun FGAA, is a GAA and Gold & Silversmiths Guild of Australia fellow. He has more than 30 years’ experience as a gemmologist and manufacturing jeweller. For more information on gemstone best practice, visit: gem.org.au

enewsletter banner 2
advertisement








Saturday, 24 August, 2019 11:22pm
login to my account
Username: Password:
Skyscraper 3 dupe
advertisement
Display 2
advertisement
Display 1
advertisement
(c) 2019 Gunnamatta Media