1. A method of determining the mineral present at a point in a sample of unknown composition, comprising: directing an electron beam toward a point on the sample to acquire an x-ray spectrum; providing a mineral definition for a first mineral, the mineral definition for the first mineral including a list of elements comprising the first mineral, each of the elements having a corresponding standard spectrum associated with the first mineral, the combination of the standard spectra associated with the first mineral forming a first combined standard spectrum; providing a mineral definition for a second mineral, the mineral definition for the second mineral including a list of elements comprising the second mineral, each of the elements having a corresponding standard spectrum associated with the second mineral, the combination of the standard spectra associated with the second mineral forming a second combined standard spectrum; comparing the acquired spectrum from the point on the sample to the first combined standard spectrum of the elements from the element list of a first mineral definition; comparing the acquired spectrum from the point on the sample to the second combined standard spectrum of the elements from the element list of a second mineral definition; determining whether the first combined standard spectrum or the second combined standard spectrum best matches the acquired spectrum; classifying the point on the sample as being composed of the first mineral if the first combined standard spectrum matches the acquired spectrum better than the second combined standard spectrum; and classifying the point on the sample as being composed of the second mineral if the second combined standard spectrum matches the acquired spectrum better than the first combined standard spectrum.