Tourmaline is a reasonably priced gemstone primarily used for jewelry and collecting and can be found all over the world. It is popular with gem collectors because it is bright and can come in almost any color. Due to its popularity, tourmaline mining is common and has existed since the early 19th century. Between 1898 and 1914, the Himalayan region was the top producer of raw tourmaline. Today, California is one of the United States’ top contributors in tourmaline. It primarily exists in Riverside and San Diego counties. These areas are only outdone by deposits that exist in Brazil.
Tourmaline is a complex mineral primarily composed of sodium, aluminum, iron, lithium, oxygen and fluorine. Its crystal shape is hexagonal. Tourmaline is usually black but is often found colored blue, red, brown, green and yellow as well. Tourmaline is rarely found by itself. It is usually embedded with granite and granodionite. It can also be found with quartzite, schist, gneiss and phyllite. In certain areas, tourmaline can be found with limestone as well.
Glass has existed naturally since the dawn of the Earth. In nature, glass forms when certain types of rock melt from high temperatures. Mass production of glass did not begin until the Industrial Revolution. Since then, many technological breakthroughs relating to glass have occurred. For one, Emil Bicheroux, a Belgian engineer, discovered a way to make glass thicker. The Pittsburgh process, another breakthrough, utilized Bicheroux’s process and the Libbey-Owens process, a technique used to shape glass into sheets. Glass, unlike tourmaline, is primarily utilized as a material rather than a gemstone. It is used in anything from car windows to tables in homes.
Being a silicate, glass is primarily composed of silicon and oxygen. Other elements in glass include calcium, magnesium and sodium. Unlike tourmaline, which has a hexagonal shape, glass does not crystallize. Glass has a high melting point at around 1,700 degrees Celsius. At this temperature, glass has been compared to syrup on a cold day. Since this temperature is hard to reach, many glassmakers add sodium oxide to production lines. This lowers the melting point and also thins the glass.