Know the purity level of your platinum wedding ring:
Platinum purity levels are measured in parts per 1000. Industry standards demand that the inner band of a platinum ring must be hallmarked, or stamped, with the platinum level. A .95 platinum wedding ring will have a hallmark of "950 plat", "950pt", or simply "platinum". A .90 platinum ring will have a hallmark of "900 plat" or "900pt", and, as most .90 platinum rings are alloyed with Iridium, you may also see "Iridplat", "900 Pt/Ir", or "900pt/10Ir". A .85 platinum wedding ring will have a hallmark of "850 plat" or "850pt", and, since it is only 85% pure, it will be quite a bit lighter. Some platinum bands will also have the alloy material and content on the hallmark. The most common alloys for platinum wedding rings are: Iridium (Ir), Ruthenium (Ru), and Cobalt (Co), so on the inside of your platinum wedding band you may see a hallmark of "50 Ir", "50 Ru", or "50 Co".

Not all .95 platinum rings are equal
100% pure platinum is very soft, which makes it malleable and easier to scratch. For this reason when making jewelry, such as platinum wedding rings, platinum will always be alloyed with another metal, making it stronger, and allowing it to resist scratching and hold a higher polish. Platinum rings can contain 5%, 10%, or 15% alloy, but pure platinum can have an alloy content of no more than 5%. Not all alloys are the same, nor indeed comparable in quality. The alloy used in your platinum wedding band makes a big difference in how your ring wears and looks. You can view photos of platinum wedding bands made with different alloys here

Iridium in platinum rings:
Iridium is the most commonly utilized platinum alloy. Iridium may be okay to use in .90 platinum bands, but for .95 pure platinum wedding rings it is just not suitable. When Iridium is used as the alloy for a platinum ring the result is a dull, grayish look, like pewter. Iridium will not strengthen the metal, so it will stay relatively soft. When platinum is combined with Iridium it will make the surface quality of your platinum wedding ring more pitted, and you will see more small cracks. Iridium alloyed platinum rings will scratch and bend with wear, and over time precious stones will come loose. It is not for quality’s sake that jewelers choose Iridium as an alloy for platinum bands, but because Iridium is cheaper, and easier to work with.

Ruthenium in platinum rings:
Ruthenium is a great alloy for certain platinum wedding ring designs. For platinum rings with a precisely balanced and fluid surface Ruthenium is what you want. A .95 platinum wedding band with a Ruthenium alloy has superior hardness, and can be polished to a beautiful mirror finish. A Ruthenium alloy will ensure your platinum band will remain free of scratches over years of wear. Ruthenium gives your platinum wedding ring a slightly darker color, which makes it noticeably distinct from white gold.

Cobalt in platinum rings:
Cobalt is in the metal class "superalloy". It is used in spacecraft and jet turbines because it gives strength even under extremely high heat conditions Cobalt will give your .95 pure platinum wedding ring almost twice the strength of other alloys. This keeps the metal free of pitting and small surface cracks. A Cobalt alloy will give your platinum band a super-hard surface, which will hold finer detail, and allow for a very durable, bright finish. The Platinum Guild International recently said, "Platinum .95/Cobalt is indisputably the best alloy for platinum casting". As an alloy for your platinum wedding ring there is nothing better than cobalt.