Marble is made of Sedimentary material (Calcium Carbonate) eg bones, shells etc) that has been in the ground for millions of years being compressed to form a very solid stone. The polish is attained by grinding to finer grits with the last stage being buffed with a light acid (called crystallization) which gives a high polish. It as well needs to be sealed but unlike Granite cannot stand up to Acids – it will lose its finish.
Quartzite is largely made of silicon, although it may contain carbonates (reactive to acids) and is a “Metamorphic” stone. This is a very tightly bound stone with extreme hardness.