HUMBOLDT MFG CO 5DPD4 - MOHRS SCALE OF HARDNESS OF MINERALS - MOHRS SCALE OF HARDNESS OF MINERALS INCLUDES 9 SPECIMENS FROM TALC TO CARBORUNDUM - EQUAL TO G7078434MANUFACTURER:HUMBOLDT MFG COMANUFACTURER PART NUMBER:5DPD4UNIT OF MEASURE:EAQTY PER UNIT OF...