Granite is an igneous (volcanic) stone made mostly of silica. It is not affected by acids or other chemicals. It’s polish is totally attained by grinding with finer and finer grits. The hardest and most tightly bound together is Red then Green, then Black, then Brown and then to the lighter colors. The lighter the color the more we sealer may be required
This is a “Metamorphic” stone however it is a very compressed form of Talc with some intrusions of other minerals brought by the flow of water. It does not take a polish but can be highly honed. It is acid/heat resistant and does not need to be sealed. It will, however, need to be treated with either mineral oil or waxes designed for use on soapstone.
Marble is made of sedimentary material (calcium carbonate) that has been in the ground for millions of years being compressed to form a very solid stone. It needs to be sealed as well, but unlike granite cannot stand up to acids as acid reacts with the calcium carbonate and essentially eats it. This is what causes marbles countertops to etch. Sealers will not stop this...
Quartzite is a metamorphic stone largely made of silicon that may contain carbonates (reactive to acids). This is a very tightly bound stone with extreme hardness. It is also vunerable to lose some of it’s polish to acids but is impossible to tell without testing.
cThis can refer to Limestone, Travertine, Slate, Schist, and/or Onyx. Natural stones aren't limited to just these however.
Limestone and Travertine are made of the same materials and therefore have the same characteristics as Marble.
Slate is a type of “metamorphic” rock formed from plant material. It tends to have an oil content. Depending on where it comes from, the size of the slabs vary. Slate is a very stable material around acid but does not take a polish.
Schist refers to a type of granite in that it usually has a quartz content that is readily visible (glitters) and tends to be a little more difficult to work because the Quartz is in layers that tend to slide against each other making it hard to keep it solid especially at the edges. It is a softer type of Granite,usually a darker color.
Onxy is an oddity of Silicon Dioxide (Chalcedony) similar to other harder stones but is smaller particles with lesser bonds to each other making it able to be sculpted. It can be said it is related to agate and usually translucent therefore perfect for backlighting.