Whenever you lay eyes on a diamond, your first thought is unlikely to be how extremely useful it is, as a stone. But many of the gemstones found in Zambia and elsewhere on the continent have important functions in industries other than jewellery-making.

Read on to discover five common uses for gemstones that don’t involve wearing them.

1. Diamonds have multiple medical uses

Diamonds are no longer just “a girl’s best friend”, as the 1950s jazz song that Marilyn Monroe popularised goes. Recent studies suggest that they may be a doctor’s best friend too. Tiny particles of the rare and valuable gemstone – called nanodiamonds – have several previously unknown health benefits. These miniature particles are one thousand times smaller than the width of a human hair, giving them the ability to attach themselves to certain drugs, most notably the chemotherapy drugs used to treat various types of cancer. Nanodiamonds help to improve the effectiveness of chemotherapy drugs by slowing down their expulsion by the human body.

Diamonds’ light-reflecting qualities also serve a purpose in the medical world. Scientists can easily track the progression of cells containing nanodiamonds by the light they reflect, thereby allowing them to monitor treatment on a cellular level. Research into diamonds’ potential for reflecting light in partially-sighted people is ongoing, and particles of this powerful stone may even be used in certain types of eye implant – or in bionic eyes – before too long.

2. Quartz crystals changed timekeeping

Although the world’s first quartz clock was built in 1927 at Bell Telephone Laboratories, the first quartz watch was only unveiled 42 years later by the watch company Seiko. Rather than being a brand, quartz watches and clocks take their name from the game-changing gemstone that has come to define timekeeping.

While both quartz clocks and their pendulum-based predecessors rely on gears to count hours, minutes and seconds, these gears are regulated in quartz watches by – you guessed it – a tiny quartz crystal, rather than a swinging pendulum. One reason that watches made with quartz are more accurate is that pendulums are affected by gravity, so they can’t tell the time consistently at different altitudes.

Diamond particles may even be used in certain types of eye implant or even in bionic eyes before too long.

It is quartz’s piezoelectric properties that allow it to measure time so accurately. Quartz generates a tiny electric voltage when it is squeezed and, similarly, a quartz crystal vibrates at a precise frequency when a small amount of voltage is applied. When it comes to telling time, the battery in a quartz clock or watch transmits electricity to the quartz crystal via a circuit, causing it to oscillate at exactly 32 768 times per second. The circuit then keeps count of the oscillations and uses them to generate one electric pulse per second. Both digital watches’ LCD displays and analogue watches’ internal motors can be powered by these electric pulses. Today, most watch manufacturers use synthetic quartz instead.

 3. Silicon chips aren’t necessarily made of silicon

The semiconductor called silicon metal that led to the development of microelectronics – and which gave us the transistor, integrated circuits, and the silicon chip – is made from pure quartz sand. But quartz-based silicon metal also has some stiff competition. Diamonds are another mineral that can replace silicon in semiconductors – and they’re more effective, too. They have incredible resistance to heat, with the ability to reach temperatures around five times higher than silicon. A diamond’s cooling process is also more efficient than silicon’s, and doesn’t affect its performance as a semiconductor. Add to this diamonds’ ability to withstand higher voltages. When compared to silicon, adding diamonds to semiconductors is a sure way to achieve a faster and generally more efficient electrical current, particularly in computers.

 4. Some stones come full circle in the mining industry

There is a certain symbiosis to the fact that, beyond their use in jewellery, diamonds are most often utilized in the mining industry itself. Diamonds’ extreme strength makes them an ideal choice of material for drill bits that can penetrate particularly hard substances. Diamond particles are also used for enhancing the efficacy of industrial saws. But it isn’t only large mines or military operations that benefit from diamonds’ strength. Even dentists’ drills are coated with traces of the valuable stone, which makes drill bits abrasive (yet delicate) enough to smooth cavities in our teeth.

Diamonds are used by jewellers to cut other diamonds, too. In fact, sands from diamonds and crystals like garnet and quartz have long been used for engraving and shaping different stones, and even to saw large slabs of rock. Today, wherever possible, synthetic crystals that can be grown in laboratories are used instead of the real thing. But when it comes to polishing stones, diamonds are arguably best polished using other diamonds. Harder gemstones like sapphire and jade also enjoy the diamond dust treatment, which shines them up like nothing else.

5. Rubies give lasers their deep red colour

Ruby lasers are, as the name suggests, made from a synthetic version of the precious red gemstone. This solid-state laser was the first successful laser to be developed in 1960, by an American engineer. It is one of very few solid-state lasers that produce visible light, and it uses synthetic ruby crystals as its laser medium.

A ruby laser’s beam creates an intense red light and has several industrial uses. You may have noticed the red light of a ruby laser in CD players, equipment used for surveying and – almost certainly – in the laser pointers that teachers and professors all over the world use during classes.

Beauty isn’t always skin deep

As eye-catchingly beautiful as many of Africa’s gemstones are, their purpose goes far beyond ornamentation. Next time you have a cavity and your dentist prepares their drill, try distracting yourself with the image of the sparkling stone that coats its tip, and be grateful for the role it will play in the health of your teeth.

See also: Five things you didn’t know about emeralds