A matrix reference material is defined as a reference material that contains major, minor, and trace components. Matrix materials are intended to be used in conjunction with the analysis of real samples of the same or a similar matrix. They are normally materials that are sampled from nature (ISO D GUIDE 30:2013(E) 2.4.).
The Matrix matched CRM should have similar chemical, mineral and grade characteristics; to the samples being tested in the laboratory. This will give the lab a fair test (see Commutability above). With reference to the major and trace element data published in the CRM certificates, particular attention should be taken to the elements most likely to cause problems in the lab.