Hobbies And Interests
Carving and Polishing Agates
Agates are considered to be the oldest known minerals and have been used over the centuries as ornaments, amulets and receptacles. Agates were especially prized stones in medieval times. In modern times, agates are still used for the same purposes and more, such as inlaid work, boxes and in the grinding equipment industry.
Large heavy blocks of agates are first sawed with circular saws with diamond blades. A special cutting fluid emulsified in water continually cools the cutting blades. This coolant is a more environmentally friendly alternative to previously used petroleum, which was not only environmentally unfriendly but also gave off strong fumes and presented fire hazards. Smaller pieces are then roughly shaped on carborundum wheels which are cooled with water. The final shaping of the stone is done on a sandstone wheel.
Polishing the stone is the final process in getting the stone ready for use. Polishing helps to give agates their luster and brings out the natural fine structural composition within the stones. The best way to polish agates is on a slow rotating wheel or cylinder made of lead, beech wood, felt or tin with the use of polishing powders like chromium oxide or Tripoli. There are no coolants used in the polishing process; hence, this is a delicate procedure, since the stones are likely to be damaged from the heat produced during the entirety of the polishing process.
The Color of Agates
Agates come in vivid multiple colors with irregular or curved bands of red, blue, gray, white, black and brown created by traces of manganese or iron. The stones may be transparent, opaque or translucent. Agates are most often cut in thin slices, as this allows the most light to pass through the stone and reveals the beauty of these bands. The more expensive variety of agates are the rough specimens such as the Brazilian stones. These are highly porous and have greater opal content. Agates are very strong stones and stand well for everyday jewelry.