The main reason why your platinum jewelry is sticking to magnets is probably because of the alloys used. Your platinum jewelry may have been combined with magnetic alloys or other magnetic or corrosive metals. Platinum is very soft, around 4-5 in the Mohs scale of hardness (only slightly harder than gold).
Platinum is commonly used in jewellery and electronics. Although this precious metal looks great and is an excellent conductor, it has no magnetic properties.
Platinum is a very rare and expensive metal. Therefore, all platinum jewelry will be marked to show authenticity. Look for the words “Platinum," “PLAT," or “PT” followed or preceded by the numbers “950” or “999." These numbers refer to the purity of the platinum, with “999” as the most pure.
Although they are paramagnetic, the platinum metals, espe- cially platinum, palladium, and rhodium, are capable of interacting in alloys with other metals to form ferromagnetic or very nearly ferromagnetic materials.
Myth Six: “Metal detectors cannot find platinum.”
This is wrong. Metal detectors can find platinum items that are buried underground or covered with sand. The thing is, people who use detectors don't find these items very often, because statistically speaking, they are rare.
As the rarest of the platinum group metals, rhodium occurs at roughly 0.000037 parts per million in the Earth's crust, while gold is found at an abundance of around 0.0013 parts per million, according to the Royal Society of Chemistry.
Platinum jewelry should be stamped “PT” for pure platinum or “PT900” or “PT950,” indicating the number of parts per thousand that are pure platinum.
Jewelry marked only “Platinum,” “Pt” or “Plat” contains at least 95-percent pure platinum. Platinum content can also be marked by 999 for 99.9% pure platinum, 950 for 95% and so on.
Are platinum rings worth anything? Yes, platinum rings are, at a minimum, worth their weight in platinum.
Metals you may encounter less often but are magnetic include neodymium, samarium, and gadolinium. The only time an item containing gold or silver could stick to magnets is if it was silver or gold plated.
Platinum is a very strong and heavy metal. The wearer of a platinum piece will have to decide if they can handle a heavier metal like platinum over a lighter metal like white gold.
Believe it or not, the chemicals present in everyday products like cleaning supplies, perfumes, hairsprays, etc. can be quite harsh. They can weaken the structure of your precious metal over a period of time. Also, the chlorine present in swimming pools can ruin the platinum's shine and cause discoloration.
Platinum is chemically inert and will not oxidize in air at any temperature. It is resistant to acids and is not attacked by any single mineral acid but dissolves readily in aqua regia. The metal is rapidly attacked by fused alkali oxides and by peroxides and will react with fluorine and, at red heat, with chlorine.
While at first glance both silver and platinum appear silver in color, the two metals are actually easily discernible to the naked eye. Both have gray undertones, unlike white gold which has a warmer, yellow undertone, but platinum is much brighter and shinier and silver has a duller, gray appearance.
Platinum, on the other hand, is a completely white metal, and never needs plating. Plating will need to be done most frequently for rings because they receive the most wear (typically every 2-5 years).
Price. Platinum: Despite being nearly identical in appearance, platinum is more valuable than gold. Platinum's high price point can be attributed to its rarity and density as precious metals are often priced by their weight.
Identifying Platinum Through Visual Cues and Weight
Pure platinum jewelry, or jewelry that is at least 50% platinum, is typically marked with a stamp (also known as a hallmark). Usually, this mark will include a number like 850 followed by “plat or “pt”, which indicates the piece is 85% pure.
Platinum was officially recognised as a precious metal for fine jewellery in 1975 when the new Hallmarking Act introduced the requirement that all articles over 0.5 grams be hallmarked.
In terms of sheer purity, platinum rings are made of at least 90-95% platinum and this density makes the band much more durable than gold. In comparison, a 14k gold ring band is typically only 58.5% gold, and the price difference reflects the quantity of the rare metals needed.
The PGM are platinum (Pt), palladium (Pd), rhodium (Rh), ruthenium (Ru), osmium (Os) and iridium (Ir). The six metals are generally found together, although their relative abundances may vary appreciably.
Palladium is currently the most expensive of the four major precious metals - gold, silver, platinum and palladium. It is scarcer than platinum, and is being used in great quantities for catalytic converters in cars.