The Superiority of Platinum over White Gold Jewellery Alloys Proven in Wear Resistance Study
Platinum Guild International releases results of multi-year research study
May 1, 2021 (Hong Kong) – Platinum Guild International (PGI) has released the findings of a formal independent study which proves the long-supported anecdotal evidence of platinum’s superiority in wear resistance and gem setting security versus that of gold jewellery. The most recent phase of research represented the third in a series of platinum wear testing studies, spanning 2016 to 2020. Conducted by fem Research Institute Precious Metals + Metal Chemistry, in association with TechForm Advanced Casting Technology and PGI, the study aimed to characterise the underlying reasons for platinum’s reported wear superiority.
Key conclusions established by the study are two-fold: platinum alloys demonstrate superior wear resistance over white gold alloys with the absolute and relative volume losses of the platinum alloys demonstrating to be lower than that of the gold alloys.
Bench jewellers will most often cite that platinum jewellery pieces that have long been in service are found to be in sound shape without extensive repairs and there is an infrequent need to re-tip platinum prongs versus gold prongs. Platinum shanks do not tend to wear thin and need replacements as often as gold shanks. As platinum is regarded as the best metal to most securely hold a diamond, the study was also conducted to measure the differences in performance of platinum alloys versus gold alloys regarding prong wear.
Six alloys were studied for the purpose of this research: two platinum alloys (950 PtRu, 950 PtIr) and four gold alloys (14K AuNi, 18K AuNi, 14Kt AuPd, and 18K AuPd). The alloys were analysed under five separate processes, including scratch testing, wear testing, corrosion testing, mechanical properties testing, and metallographic examination via optical and scanning electron microscopy.
Platinum Alloys (in blue) show volume loss up to 3X lower compared to 18K palladium white gold, and a factor of about 2X lower compared to 14K palladium white and both 14K and 18K nickel white gold
“After years of testing, these comprehensive findings confirm significantly lower volume loss on platinum jewellery alloys versus common white gold jewellery alloys” said Teresa Frye, President of TechForm Advanced Casting Technology. “Through the use of standardized testing designed for jewellery purposes we were able to successfully replicate observations of platinum’s superior wear resistance made by bench jewellers across the world.”
Huw Daniel, CEO of PGI shared, “This research has provided conclusive evidence that platinum is without doubt, the superior precious metal for fine jewellery. Its beauty is matched by performance characteristics that include better wear over time, and the securest setting for diamonds, good reasons to provide peace of mind to jewellers and consumers around the world.”
A final phase of research with additional alloys used across international markets is currently being conducted. The report’s published results in the Johnson Matthey Technology Review (JMTR) are available at https://www.ingentaconnect.com/content/matthey/jmtr/pre-prints/content-jm_jmtr_fryetjul21# and will be included in the upcoming July issue of the JMTR.