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Palladium Plating

Please be aware that the palladium calculator is for solid palladium jewelry. Solid palladium jewelry contains a uniform mixture of palladium and other metals throughout the entire piece of jewelry. For instance, a 10g piece of 950 solid palladium jewelry contains 95% palladium or 9.5 g of pure palladium.

On the other hand, palladium plated jewelry contains almost no palladium. Palladium is an expensive metal and it is cheaper to use other metals to make jewelry. To make palladium jewelry more affordable whilst enjoying the aesthetic appeal from the color of palladium metal, a very small amount of palladium can be applied to the exterior of the jewelry instead of using it uniformly through the jewelry. Hence, palladium plated jewelry is usually a fraction of the cost of solid palladium jewelry. Palladium plating has the benefit of being resistant to corrosion and is hypoallergenic which reduces the likelihood of allergic reactions.

• Palladium layered - a very thin layer of palladium.
• Palladium plated or palladium electroplated - uses an electric current and a piece of jewelry, which acts as an electrode, inside a palladium solution. The palladium forms a coherent metal coating on the electrode.
• Palladium overlay or rolled palladium plated - Uses a heat or pressure bonding process to mix and bond the metals together.

To recap, palladium plated jewelry contains an almost negligible amount of palladium metal. The palladium calculator is only applicable to solid palladium jewelry, not palladium plated jewelry.

Palladium Hallmarks

A hallmark is a mark stamped on a piece of jewelry certifying the purity of metal used. There are hallmarking laws that apply to the sale of palladium jewelry in some countries (such as the Hallmarking Act 1973 in the UK). However, globally there is no standard that must be followed therefore solid palladium jewelry may or may not be hallmarked.

Solid Palladium Hallmarks

Solid palladium jewelry will have its purity stamped on it. The purity is expressed in fineness scale which is expressed as parts palladium per thousand, or less commonly, as a percentage (%). Please refer to the scrap metal price table for the relationship between percentage and fineness. It will usually be written with "PD", "PALL" or even "PALLADIUM" next to the fineness.

Please be aware that palladium jewelry may be hallmarked a certain fineness and may not have that level of palladium content or may not be solid palladium jewelry at all. Hence palladium jewelry needs to be tested when valuing its palladium metal content.

You may choose to scratch a suspected plated piece deep enough to see the underlying metal to confirm the jewelry is not solid palladium. As this is a destructive test, choose a discreet spot which will not be visible when worn, for example, around the clasp on a palladium chain.

Palladium Testing

As a palladium buyer this is important to remember palladium metal is expensive relative to most other metals therefore there is always an economic incentive to pass lower content palladium as higher content palladium. Hence, remember to test for palladium purity.

Density Test

Measure the mass of the jewelry (in grams) and then put the jewelry in a small beaker that has water in and see how much the water level rises (mL). The unit millilitres (mL) is equal to the unit cubic centimetre (cm3) (1 mL = 1 cm3). By dividing the mass in grams by the water displaced in millilitres (mL) you will get the density of the jewelry in grams per cubic centimetre (g/cm3). Pure palladium is 11.9 g/cm3.

X-Ray Fluorescence

This method of testing is non-destructive and is suitable for normal assaying requirements. A computer, called a x-ray fluorescent (XRF) analyzer, will use x-rays to determine the composition the the jewelry. It takes less than a few minutes to complete and the results may be printed out. Popular brands include Thermo Scientific Niton range or Olympus GoldXpert or DELTA Precious Metals XRF analyzers.

There is also a method called x-ray fluorescence assay which involves melting a sample into a uniform composition before testing the sample on a XRF analyzer. This method is more accurate then a XRF analyzer but less accurate then a fire assay.

Fire Assay

This method of testing is totally destructive however provides the greatest accuracy. The first part of the process is called fusion which involves mixing the sample with a fluxing agent (which helps melt, fuse, and separate the precious metal) and heating it to a high temperature. The second part of the process is called cupellation which involves using a collector, such a nickel or lead, to extract the precious metals.

The precious metals extracted from fire assay is then analyzed by one of the following methods:

• Flame Atomic Absorption (AA)
• Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES)
• Inductively Coupled Plasma-Mass Spectrometry (ICP-AES)
• Instrumental Neutron Activation Analysis (INAA)

Miscellaneous Equipment

Other equipment that is common in palladium testing kits include:

• Jewelers loupe provides magnification to see small details more closely. Handy for inspecting hallmarks.
• Digital scale for precisely measuring the weight of jewelry.
• Magnet for testing if there are magnetic metals in the jewelry.
• Diamond tester for confirming a precious stone is a genuine diamond (or moissanite).