GLASS: THE NATURAL FORMS
It exists naturally in a glassy or vitreous state as obsidian and tektites.
Obsidian is semi-translucent, and can be of three hues, viz., red, black and brown. It is produced as magma (molten igneous rock) forces its way out (during volcanic eruption) and cools down rapidly on reaching the earth’s surface. The cooling effect takes place so fast that the ions within it cannot crystallize.
Tektites are enigmatic small dark-colored entities scattered in an S-shaped belt over the earth’s crust. Their irregular shapes and glassy composition is believed to have extraterrestrial connections. This belt spreads from Georgia and Texas to South America, the western coast of Africa, Eastern Europe, south-eastern Asia and Australia.
The utility of naturally available glass was known to mankind since the Stone Age. The early man flaked stones to use the glass flints for making tools and weapons. However, the earliest glass objects were beads. The excavated hollow glass vessels date back to 1500 BC.
Glass chandelier is a popular branched designer lighting shade. This lighting tool is made of glass that passes through varied processes to get the desired glaze, shape, design, color and durability. The price ranges also differ starting from the quite economical ones to the ones that have an exorbitant tag. see more here: https://www.duttonbrown.com/pages/globe-pendant-lighting
Glass is mixed with many other compounds to render it the aforementioned characteristics. For instance, the very ingredients used to manufacture the most popular form of such a lighting shade – crystal or glass chandelier – are primarily lead and glass. Hence crystal is also christened lead glass.
This fine glass is manufactured from potassium-silicate formulae involving lead oxide. It is heavy and possesses an increased capacity to refract light. This facility makes it an ideal compound to design prisms, imitation jewels, and lenses.
Lead can absorb high-energy radiation too. So, lead glasses are also utilized to make shields for personnel working in nuclear stations.
So what is glass exactly?
Glass is an amorphous material manufactured from silica fused at very high temperatures with phosphates or borates. Though its state is glassy or vitreous, and the molecular elements remain disordered yet there is mechanical rigidity to render cohesion. When this state of glass is cooled it does not develop crystallization but attains a solid shape. Once reheated, it transforms into the liquid form.
It can be opaque or translucent. The color changes in accordance to the ingredients.