A practical image analysis technique for estimating the weight of abraded mineral fractions used in U-Pb dating
Wm. H. Matthews, W J Davis · 1999
A simple method for estimating the weight of abraded zircon grains from a digital photomicrograph is presented. It requires less than five minutes, uses image analysis software to determine the lengths of the two principal axes of a zircon grain from a digital image, and, combined with user-specified morphological characteristics, calculates the weight using an empirically derived factor. The accuracy of the method is demonstrated using ten abraded zircon fractions of varied morphologies and sizes. Model weight calculations for nine of the ten samples are within ±10 per cent of the weights measured by an electronic microbalance. The method can be used for single grains or individual grains in a multigrain fraction. This method is unlikely to eliminate entirely the need to weigh zircon samples, but it will help reduce or eliminate grain loss between the selection and microchemistry stages for many analyses.