What is glass made of?

Answer 1

The ordinary glass is a mixture of sodium silicate, calcium silicate and Silicon dioxide, Na2SiO3.CaSiO3.4SiO2
There isn't just one ingredient used in glass, and there are different fusions of minerals to make it as well. Check out this paragraph, it tells of a few different types of glass that we use today.

From the wikipedia site:

Pure silica (SiO2) has a "glass melting point"- at a viscosity of 10 Pa·s (100 P)- of over 2300 °C (4200 °F). While pure silica can be made into glass for special applications (see fused quartz), other substances are added to common glass to simplify processing. One is sodium carbonate (Na2CO3), which lowers the melting point to about 1500 °C (2700 °F) in soda-lime glass; "soda" refers to the original source of sodium carbonate in the soda ash obtained from certain plants. However, the soda makes the glass water soluble, which is usually undesirable, so lime (calcium oxide (CaO), generally obtained from limestone), some magnesium oxide (MgO) and aluminum oxide are added to provide for a better chemical durability. The resulting glass contains about 70 to 74 percent silica by weight and is called a soda-lime glass.[8] Soda-lime glasses account for about 90 percent of manufactured glass.

As well as soda and lime, most common glass has other ingredients added to change its properties. Lead glass, such as lead crystal or flint glass, is more 'brilliant' because the increased refractive index causes noticeably more "sparkles", while boron may be added to change the thermal and electrical properties, as in Pyrex. Adding barium also increases the refractive index. Thorium oxide gives glass a high refractive index and low dispersion, and was formerly used in producing high-quality lenses, but due to its radioactivity has been replaced by lanthanum oxide in modern eye glasses. Large amounts of iron are used in glass that absorbs infrared energy, such as heat absorbing filters for movie projectors, while cerium(IV) oxide can be used for glass that absorbs UV wavelengths (biologically damaging ionizing radiation).

Two other common glass ingredients are calumite (an iron industry by-product) and "cullet" (recycled glass). The recycled glass saves on raw materials and energy. However, impurities in the cullet can lead to product and equipment failure.

Finally, fining agents such as sodium sulfate, sodium chloride, or antimony oxide are added to reduce the bubble content in the glass.[8] Glass batch calculation is the method by which the correct raw material mixture is determined to achieve the desired glass composition.

Sand mostly.
glass is made from sand which they heat to make it transparent....... also right now the glass from anything in melting but so slowly that it will take about over 1 million years for it shrink considerably. sorry but i don't why is is made out of that. probably because sand is a solid and you can melt it to make it transparent.
it is made out of melted sand which includes ionic compounds that form lattices, this is what makes glass strong.

Answer 2

Glass is silicon which is essentially sand mixed with certain chemicals and sometimes lead and then heated in a furnace until it becomes liquid. In the liquid state. it is shaped either by hand or pressed into the glass molds to make the objects that we use in our evry day life.