This week’s question was asked by a friend.
QUESTION: Are diamonds good for anything besides jewelry?
ANSWER: Diamonds may be “a girl’s best friend,”, but an industrial worker might say “diamonds are a machinist’s best friend.” Over 80 percent of natural diamonds are used for industrial purposes. The remaining 20 percent go into jewelry.
Diamonds are made of carbon, a very common element that is in coal, trees, pencils and you and me. There are no trace elements in diamonds, just pure carbon. The crust of the Earth has been subjected to tremendous heat and pressure. Carbon is crushed and squeezed until its atoms are forced into a particular crystal lattice that sort of looks like little pyramids.
Diamonds are used in industrial applications, especially for drilling, sawing and sanding. The diamond tips render these tools capable of drilling and cutting through materials which they might otherwise not be able to impact. Diamond dust is used for grinding with tiny specks of diamond embedded in disc sanders.
Diamond is hard, one of the hardest known substances occurring in nature. The Moh scale was created in 1812 by German geologist and mineralogist Friedrich Mohs. The scale, going from one to 10, is used to roughly identify minerals and their hardness by using scratch kits. On that Moh scale, talc is a one, gold and silver are at 2.5, copper is a three, quartz is seven, and you guessed it, diamond is a perfect 10.
About 60,000 pounds of diamonds are mined each year on planet Earth. Africa has diamond mines in Angola, Botswana, Congo, Sierra Leone and South Africa. Brazil and Australia host diamond mines. Since the 1950s, the value of natural diamonds is based on a globally accepted standard of the 4Cs, color, clarity, cut and carat weight.
Diamonds are made only of carbon, so they can be made artificially. Oddly, synthetic diamonds are not good as jewelry diamonds because they are too good; too perfect. They have no interesting color or characteristics. Synthetic diamonds are ground down into powder and used as an abrasive.
About 60,000 pounds of diamonds are mined each year, but about 240,000 pounds are made synthetically in factories.
Diamonds are hard, but not tough. They will break easily when subjected to pressure. As a matter of fact, that is how a diamond is cut, by pounding on it so it cleaves or breaks.
Diamonds are both good and bad electrical conductors. Most are electrical insulators. They don’t conduct electricity. However, blue diamonds are good electrical conductors. Blue diamonds get their blue from boron impurities, and boron is a good electrical conductor.
Diamonds do not interact with strong acids and strong bases. They are chemically stable and very difficult to oxidize.
Some real diamonds from the Earth don’t make the grade. They may be lacking in gemstone quality (the four Cs). They are referred to as “bort.” They are largely opaque, making them undesirable for most jewelry applications.
Some industrial diamonds act as ball bearings. Diamonds are excellent heat conductors and are used as heat sinks in electronic circuits, carrying away excessive heat. Some diamonds are used in semiconductors.
The popularity of diamonds in jewelry is largely due to a big marketing push from the famous De Beers in the 1930s and 40s. Diamonds are indeed beautiful, but so are many other gemstones. The only real reason that “diamonds are forever” in terms of jewelry is because it was a famous marketing slogan. Nonetheless, diamonds have undeniable practical value in industry.
Even though the phrase “diamonds are forever” may have been a marketing invention, there’s no denying that it has some basis in reality. When you give someone special the gift of a diamond engagement ring, you are telling that person that your bond is as unbreakable as the diamond.
Send questions and comments to: email@example.com.
Larry Scheckel is a retired Tomah High School physics teacher.