Platinum
Pure platinum is a lustrous, ductile, and malleable, silver-white metal. Platinum is more ductile than gold, silver or copper, thus being the most ductile of pure metals, but it is less malleable than gold. The metal has excellent resistance to corrosion, is stable at high temperatures and has stable electrical properties. Platinum does oxidize, forming PtO, at 500 °C; this oxide can be easily removed thermally. It reacts vigorously with fluorine at to form platinum tetrafluoride. It is also attacked by chlorine, bromine, iodine, and sulfur. Platinum is insoluble in hydrochloric and nitric acid, but dissolves in hot "aqua regia" (A mixture of nitric and hydrochloric acids), to form chloroplatinic acid, HPtCl.
Zari
In ancient times, when precious metals were cheaply and easily available, only real zari threads were produced. Due to industrial revolution and invention of electroplating process, imitation techniques came into existence to cut the cost of precious metals. As copper is the most malleable and ductile metal after gold and silver, silver electroplated copper wire replaced pure silver. Various modern colours and chemicals are used to create/impart a golden hue instead of pure gold. The precious metals and copper too became dearer due to huge demand in various modern industries. Thus, a cheap and durable alternative was invented with non-tarnishing properties. Metallic zari came into vogue replacing traditional metals like gold, silver & copper. This non-genuine modern zari is light in weight & more durable than earlier editions. Also, it has the sought after properties of resistance to tarnishing and knotting.