I've found another term people used for this word: Rose gold/Red gold. the two are the same type of metal alloy (gold and copper) but with different percentage of mixtures.
http://encyclopedia.thefreedictionary.com/Rose gold
http://jewelry.novica.com/necklaces/copper/gold-plated-neckl...
The pinchbeck i noticed that the english definition says its a alloy of zinc and copper
http://encyclopedia.thefreedictionary.com/List of alloys
another one i just found
http://www.sec.psu.ac.th/web-board/?pid=view_replies&thread_...
How do you think?