Abstract: Apparatus and methods are disclosed for efficiently and quickly determining the exact location of spicules of calcium within a test specimen of human tissue removed from a woman's breast. By exactly locating the clusters of calcification, a pathologist can dissect the portion of the test specimen containing the calcifications and quickly analyze the same to determine whether or not malignancy exists. A pair of grid plates is provided, one on top of the other, with clamping means to compress a test specimen therebetween in the present invention. The plates include a grid system which is opaque to radiographic filming which allows the determination of the exact location of the clusters of calcifications.