How do you think the Egyptians were able to work with such hard stones

There exists a category of artifacts from the earliest times of ancient Egypt Hearthstone phases. Vessels dishes and more ranging in size from large to very small made from a wide range of igneous Stone. Like Granite diorite pour free slate schist cyanite rock crystal or even corundum all incredibly hard materials harder than steel ranging from six to nine. On the most scale of hardness. They display truly remarkable characteristics of precision manufacturing perfect Symmetry and balance Immaculate polished and smooth surfaces. Machining and turning tool marks on the interiors and some with an astonishing thinness of material translucent Stone down to even 1 40th of an inch thick truly challenging as these types of hard. Stones become brittle when thin and carving them is no simple task. The stone Matrix goes from softer materials like Mica or hornblend to very hard materials like the obvious large quartz.