Fluorapatite, Quartz, Magnetite?    Cerro de Mercader, Durango, Mexico.  Ex. John Davis collection.  Several complete and incomplete gemmy yellow crystals are embedded in this 5.8 x 4.3 x 3 cm piece.  The matrix is composed of what appears to be large magnetite crystals.  The piece should have some of the coatings lightly chipped off with a razor blade to make the crystals stand out better.  $55