Updated on 19 October, 2021
Niton is one of the most popular laboratory minerals due to its high purity and excellent resistance to damage. It is the most abundant mineral in Australia. It has a very high melting point and very little alloying, making it the perfect choice for many laboratory applications including purity testing. The majority of precious metals, including platinum, gold and silver are made from some form of Niton. The best way to store Niton is in an airtight container, but as the metal itself does not lend itself well to storage through the use of dry ice or vacuum methods, it is often given the option of a 'hot plate' to melt the Niton at room temperature in order to use it for other purposes such as testing.
In addition to purity testing, most labs also carry out precious metals testing for the purpose of checking for impurity levels. Such testing is carried out on a part by piece, each component being subjected to various parameters to find out whether there are any foreign bodies or contaminations present in the sample. Many times, when precious metals are tested, it is found that there is some element present in the sample which should not have been there, due to a variety of reasons, ranging from simple contamination to structural damage. These tests help in identifying what, if any, foreign bodies may be present in the samples. The desired shape and size of the alloy may also require a specific amount of purity, so that if there are too many impurities present in the raw materials, the desired shape and size may not be achievable.
Many advantages are associated with the use of x-rays in Precious Metals testing and analysis. The radiation emitted by the x-ray beam penetrates quite deep into the metal object to reach the inner layer, thus giving accurate results. The depth can be adjusted depending upon the desired accuracy, and even a slight error in the depth penetration does not affect the results significantly. Through the years, the use of x-rays in Precious Metals Testing has improved a great deal, as more sophisticated technology has allowed for better pictures to be taken and deeper penetrations. In fact, the latest equipment used for Precious Metals testing produces detailed images that are easy to interpret.
When it comes to Precious Metals testing, it is essential that both the tester and the laboratory work hand in order to achieve the desired results. The x-ray fluorescence test is one such method often used for Precious Metals analysis. This method involves exposing the sample to x-rays of varying energies. The energy of the x-rays depends on the type of precious metal being tested, and the tester uses a device known as an x-ray fluorescence detector to determine if there is an inelastic collision or inelastic absorption of the precious metal in question. The detector uses electromagnetic radiation produced by the x-ray source itself. Once the energy of the emitted radiation is detected, a computer helps the tester to analyze the data.
Another form of Precious Metals testing is known as spot assays. These type of assays are typically performed on nonmagnetic surfaces, where magnetic properties may affect the presence of Precious Metals. For instance, a magnetic surface exposed to strong magnetic fields can cause a reduction in the density of the metal, which can affect its weight. Alternatively, metals which have a high porosity can be weighed without using any metal probes, which will reveal their weight in terms of their conductivities.
Other Precious Metals Assay techniques include finality, which measures the fineness of a precious metal by weighing the alloy at a specific weight. The tester then compresses the alloy and weighs it. The results of the compression are interpreted by the tester as the density of the alloy, its electrical conductivity, the amount of lead that will be found in the alloy, and other useful data. While finality is an accurate method of assessing Precious Metals Purity, it has been found that the majority of precious metal assays do not employ this technique.
In addition to finality, another way of Precious Metals Testing is known as the analytical method. This method of testing Precious Metals involves several steps, including analysis by means of various methods in order to determine the purity of the metal. The first step in the process would be to heat the metal in order to melt its impurities, such as iron or aluminum. After this has been done, the metals would then be placed in a container, where specific ions of the desired metal can be detected by sensitive methods. In case the metal contains any excess iron or aluminum, these particles can be removed by means of a separate method, for example ionization, before carrying out the analysis.
The final step in Precious Metals Testing is the definitive test, which is carried out once all the desired results have been achieved, using both X-rays and Electron Microscopy. When carrying out Precious Metals Testing, one should remember to wear protective gloves and masks, as well as goggles, in order to protect the eyes from the harmful rays. The entire process will normally need to be carried out at room temperatures, so ensure you have a suitable environment set up when performing this task. Overall, it is important to learn more about the process of Precious Metals Testing, and how it can help you to evaluate your Precious Metals Assay results.