Editing Palladium (section)

===Jewellery===
Palladium has been used as a [[precious metal]] in jewellery since 1939 as an alternative to platinum in the alloys called "[[white gold]]", where the naturally white color of palladium does not require [[Plating#Rhodium plating|rhodium plating]]. Palladium, being much less dense than platinum, is similar to gold in that it can be beaten into [[Metal leaf|leaf]] as thin as 100&nbsp;nm ({{frac|1|250,000}}&nbsp;in).<ref name="CRC" /> Unlike platinum, palladium may discolor at temperatures above {{convert|400|C|F}}<ref>{{cite book |first1=Dinesh C. |last1=Gupta |first2=Paul H. |last2=Langer |author3=((ASTM Committee F-1 on Electronics)) |title=Emerging semiconductor technology: a symposium |url=https://books.google.com/books?id=u-a9LvarW-8C&pg=PA273 |date=1987 |publisher=ASTM International |isbn=978-0-8031-0459-4 |pages=273–}}</ref> due to oxidation, making it more brittle and thus less suitable for use in jewellery; to prevent this, palladium intended for jewellery is heated under controlled conditions.<ref>{{Cite web |last=Mann |first=Mark B. |date=2007 |title=950 Palladium: Manufacturing Methods |url=https://www.ganoksin.com/article/950-palladium-manufacturing-methods/}}</ref>

Prior to 2004, the principal use of palladium in jewellery was the manufacture of white gold. Palladium is one of the three most popular alloying metals in white gold ([[nickel]] and silver can also be used).<ref name="unctad">{{cite web |publisher=[[United Nations Conference on Trade and Development]] |url=http://www.unctad.org/infocomm/anglais/palladium/uses.htm |title=Palladium |access-date=5 February 2007 |archive-url=https://web.archive.org/web/20061206003556/http://www.unctad.org/infocomm/anglais/palladium/uses.htm <!--Added by H3llBot--> |archive-date=6 December 2006}}</ref> Palladium-gold is more expensive than nickel-gold, but seldom causes allergic reactions (though certain cross-allergies with nickel may occur).<ref>{{cite journal |last1=Hindsen |first1=M. |last2=Spiren |first2=A. |last3=Bruze |first3=M. |title=Cross-reactivity between nickel and palladium demonstrated by systemic administration of nickel |journal=Contact Dermatitis |volume=53 |issue=1 |pages=2–8 |year=2005 |pmid=15982224 |doi=10.1111/j.0105-1873.2005.00577.x |s2cid=20927683}}</ref>

When platinum became a strategic resource during World War II, many jewellery bands were made out of palladium. Palladium was little used in jewellery because of the technical difficulty of [[Casting (metalworking)|casting]]. With the casting problem resolved<ref>{{cite web |last1=Battaini |first1=Paolo |title=The Working Properties for Jewelry Fabrication Using New Hard 950 Palladium Alloys |url=http://www.santafesymposium.org/2006-santa-fe-symposium-papers/2006-the-working-properties-for-jewellery-fabrication-using-new-hard-950-palladium-alloys |website=SANTA FE SYMPOSIUM PAPERS |date=2006}}</ref> the use of palladium in jewellery increased, originally because platinum increased in price whilst the price of palladium decreased.<ref name="wsj">{{cite news |last=Holmes |first=E. |title=Palladium, Platinum's Cheaper Sister, Makes a Bid for Love |publisher=[[The Wall Street Journal]] (Eastern edition) |date=13 February 2007 |pages=B.1}}</ref> In early 2004, when gold and platinum prices rose steeply, China began fabricating volumes of palladium jewellery, consuming 37 [[tonne]]s in 2005. Subsequent changes in the relative price of platinum lowered demand for palladium to 17.4 tonnes in 2009.<ref name="USGS09YB">{{cite web |publisher=[[United States Geological Survey]] |date=January 2007 |title=Platinum-Group Metals |work=Mineral Yearbook 2009 |url=http://minerals.usgs.gov/minerals/pubs/commodity/platinum/myb1-2009-plati.pdf}}</ref><ref name="USGS06YB">{{cite web |publisher=[[United States Geological Survey]] |date=January 2007 |title=Platinum-Group Metals |work=Mineral Yearbook 2006 |url=http://minerals.usgs.gov/minerals/pubs/commodity/platinum/myb1-2006-plati.pdf}}</ref> Demand for palladium as a catalyst has increased the price of palladium to about 50% higher than that of platinum in January 2019.<ref name="JMM">{{cite web |date=2019 |title=Johnson Matthey Base Prices |url=http://www.platinum.matthey.com/prices/price-tables |access-date=7 January 2019}}</ref>

In January 2010, [[hallmark]]s for palladium were introduced by assay offices in the United Kingdom, and hallmarking became mandatory for all jewellery advertising pure or alloyed palladium. Articles can be marked as 500, 950, or 999 parts of palladium per thousand of the alloy.
<!-- Johnson Matthey estimated that in 2004, with the introduction of palladium jewellery in China, demand for palladium for jewellery fabrication was {{convert|920,000|ozt|MT}}, or approximately 14% of the total palladium demand for 2004&nbsp;— an increase of almost {{convert|700,000|ozt|MT}} from the previous year. This growth continued during 2005, with estimated worldwide jewellery demand for palladium of about {{convert|1,400,000|ozt|MT}} 1.4&nbsp;million ounces (44&nbsp;t), or almost 21% of net palladium supply, again with most of the demand centered in China. 37,000&nbsp;kg in 2005 15,500 (2007) 20,200 (2008) 17,400 (2009) -->

[[Fountain pen]] [[nib (pen)|nibs]] made from [[gold]] are sometimes plated with palladium when a silver (rather than gold) appearance is desired. [[Sheaffer]] has used palladium plating for decades, either as an accent on otherwise gold nibs or covering the gold completely.

Palladium is also used by the luxury brand [[Hermès]] as one of the metals plating the hardware on their handbags, the most famous of which is Birkin.