Platinum is a precious metal that is valuable and attractive in jewellery design. Rings that are made of platinum are often used to host a solitaire diamond or other gemstones in a bridal set, thus adding more value and sentiment to the ring design. The rarity, durability, and heavy qualities of platinum make it one of the most popular metals for ring design. Due to platinum's silvery white appearance, it can often be mistaken for white gold or sterling silver. Whether the ring is brand new or in used condition, identifying platinum in a ring can be worthwhile.
Use a magnifying glass or a jeweller's loupe to study the markings on the ring. Look on the inner shank of the ring for any detailed letters or numbers. If the shank has a visible, "PT" symbol, reads "900 PLAT"or has "950 PLAT" markings, then the ring is definitely platinum. If the ring shows a 9K, 10K, 14K, 18K, 22K, with or without a series of three numbers, then the ring is not platinum. If the inside shank reads GF, GE, HGE, RGP or GP, the ring is not platinum.
Place the ring over heat. Use an oven glove, and place the ring in a metal spoon. Hold the spoon over a gas stove flame. Watch to see if the spoon and the ring change colours. If the spoon changes colours and the piece of jewellery does not, it is probable that the ring is made of platinum. Platinum has a very high melting point and will not change colours when it is exposed to heat like other metals.
Use a platinum metal test kit. Metal test kits use acid to check for the existence of platinum. Rub the ring on a test stone, and add a drop of acid to the metal streak on the stone. Notice the reaction time of the drop of acid. Unlike many metals, platinum is stable in its chemical make-up and will not react immediately to the acid drops. If it takes awhile for the reaction to occur, there is a strong chance that the metal could be identified as platinum.
Weigh the ring, and compare it to another ring of similar size that you know is gold. Use a digital scale that is designed to weigh gold for the most accurate results. Place the ring on the digital scale and the weight in grams will be displayed. If a digital scale is not readily available, use a household scale that measures in grams to compare the two rings. Without a scale, it is possible to place one ring in each hand and compare the weight between the two hands. This method will provide the least accurate results. If the ring in question is noticeably heavier than the gold ring, there is a good chance that it is platinum. According to preciousplatinum.com, a platinum ring will be about 40 per cent heavier than a ring made of gold. Platinum is a dense metal in comparison to gold. It is possible to identify a platinum ring based on its heavy weight.
Take the ring to a jeweller. Allow a professional jeweller to examine and weigh the ring. In general, a professional jeweller will be able to correctly assess the ring without having to run extensive tests. For most professional jewellers, platinum will be visually recognisable and identifiable by weight. For an added fee, a jeweller will be able to run chemical tests to determine with 100 per cent accuracy whether the ring is platinum.
When using a magnifying glass or a jeweller's loupe, examine the ring in natural light. Natural light provides the best light source for accurately reading the shank of the ring.
Some metals could melt when heated over a gas flame, so only choose this option if it is worth the risk. High quality gold, fake gold, rhodium plating and alternative alloys could melt in the heating process.