Ancient Civilizations The history of civilization is a long one. This sites take you way back into history to see human civilization as it first looked. Ancient Civilizations in General Ancient civilizations arose all over the world.ncient Civilizations The history of civilization is a long one. This sites take you way back into history to see human civilization as it first looked. Ancient Civilizations in General Ancient civilizations arose all over the world.
Quartz is one of the most well-known minerals on earth. It occurs in basically all mineral environment s, and is the important constituent of many rock s. Quartz is also the most varied of all minerals, occurring in all different forms, habits, and colors.There are more variety names given to Quartz than any other mineral. The blue variety of Quartz, which is very uncommon in nature and rarely in crystal form. Most Blue Quartz is what is popularly known as Aqua Aura, essentially clear Rock Crystal synthetically irradiated with gold to form a deep sky blue color.
Quartz is very resistant to both chemicals and heat. It is therefore often used as a foundry sand. With a melting temperature higher than most metals it can be used for the molds and cores of common foundry work. Refractory brick are often made of quartz sand because of its high heat resistance.Quartz sand is also used as a flux in the smelting of metals.he high hardness of quartz, seven on the Mohs Scale, makes it harder than most other natural substances. As such it is an excellent abrasive material. Quartz sands and finely ground silica sand are used for sand blasting, scouring cleansers, grinding media, and grit for sanding and sawing.