do people invest in it?
Yes, as it finds use in jewellery, usually as a 90–95% alloy, due to its inertness.
Platinum
 Platinum finds use in jewellery, usually as a 90–95% alloy, due to its inertness. 
where are the heaviest metals located in a periodic table Columns 3 to 16 which are some of these found in the environment? Iron, copper, tin, silver, gold, and platinum. what are the physical properties of the last element? It has excellent resistance to corrosion, is stable at high temperatures and has stable electrical properties. which country was the first to discover it? UNANSWERABLE
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Platinum [SEP] As an investment
Platinum is a precious metal commodity; its bullion has the ISO currency code of XPT. Coins, bars, and ingots are traded or collected. Platinum finds use in jewellery, usually as a 90–95% alloy, due to its inertness. It is used for this purpose for its prestige and inherent bullion value. Jewellery trade publications advise jewellers to present minute surface scratches (which they term patina) as a desirable feature in attempt to enhance value of platinum products. In watchmaking, Vacheron Constantin, Patek Philippe, Rolex, Breitling, and other companies use platinum for producing their limited edition watch series. Watchmakers appreciate the unique properties of platinum, as it neither tarnishes nor wears out (the latter quality relative to gold).