Diamonds are forever

What are diamonds used for besides jewelry?

Q: Some diamonds may be “a girl’s best friend,” but there are other kinds of “diamonds.” Can you name a few?

A: Diamonds, a particular form of carbon, are the hardest material we know of, typically formed under extremes of pressure and temperature deep in the Earth’s mantle, reports Gemma Tarlach in Discover magazine. Actually, only a small fraction of diamonds are cut for jewelry. Naturally transparent, any hint of color indicates some imperfection: A trace of nitrogen atoms can make the rock appear yellow or brown; a few boron atoms create a blue color, as in the famous Hope Diamond.

Yet most diamonds end up in an industrial setting. In 1955, labs at General Electric created diamonds from carbon-based graphite, mimicking nature in subjecting it to extremes of pressure and temperature. Now, synthetic diamonds are routinely used in industrial settings for drilling and grinding.

Finally, of course, diamonds appear on playing cards. Likely invented in China more than a millennium ago, the cards apparently spread along trade routes, first to Egypt and then to Europe by the 14th century.

Initially, European merchants kept the original four suits of swords, wands, cups and coins, but by the late 1400s, the French had developed the ones we know today. True to form, diamonds still represent the merchant class and wealth acquisition.

Q: What remarkable act do lowly Matabele ants — alone among non-human animals — share with Homo sapiens?

A: “Nurse” ants actually treat their comrades’ injuries, licking the lacerations of the fallen and helping them survive, reports Jasmin Fox-Skelly in New Scientist magazine. On a daily basis, soldier ants hunt termites, dragging them from their nests and carrying them back home.

But not without a fight. The termites’ powerful jaws can inflict lethal bites, and ants often lose limbs. Yet by releasing a pheromone, they prompt other ants to carry them to safety.

When researcher Erik Frank and colleagues at the University of Lausanne in Switzerland filmed this nest activity, they found that nurse ants spend several minutes licking their comrades’ wounds, 90 percent of which survived. Without such care, 80 percent of those that had lost limbs were dead within a few hours (“Proceedings of the Royal Society B”). The treated ants, even those missing a leg or two, went on to run again at normal speeds.

Which leads to another interesting point: It’s unlikely that the ants felt compassion but rather wanted to keep their numbers up, says Frank: “The rescuers were selective in who they picked up … They didn’t want to help heavily injured ants that had lost five legs.”