Being simply "pretty" is never enough. Gemstones follow a set of strict, globally recognized rules. Whether a stone can officially be called a gemstone comes down to four uncompromising criteria:

- Beauty: It must have stunning color, transparency, and fire (the way it disperses light into rainbow flashes).  
- Durability: A Mohs hardness of at least 7.5 - resistant to scratches, stable under heat, and unaffected by acids.  
- Rarity: Naturally scarce in the earth, and even lab-grown versions are difficult to produce.  

The most famous precious gemstones are diamond, ruby, sapphire, and emerald. With the exception of emerald (which is 7.5–8), all of these have a Mohs hardness of 9 or higher. Other well-respected gems include spinel, chrysoberyl (especially cat's-eye and alexandrite), tourmaline, and more.

Now, a special mention goes to moissanite. Moissanite's chemical name is silicon carbide (SiC). It was first discovered in 1893 by French chemist Henri Moissan inside a meteorite crater, which is why it's sometimes romantically called "a gemstone born from the stars". Natural moissanite, however, is extraordinarily rare - virtually no crystals clean enough for jewelry use have ever been found on Earth.

So scientists recreated the extreme heat and pressure of a meteorite impact in the lab, carefully controlling purity, and learned how to "grow" it. Today, every piece of jewelry-grade moissanite comes from a lab.

Moissanite has the second-highest hardness of any gem material - 9.25 on the Mohs scale (just below diamond's perfect 10), and it possesses more than twice the fire/brilliance of diamond. Yet its price is only about 1/20 of a natural diamond and roughly 1/3 of a lab diamond, making it the rising star of 21st-century gemstones.

At Ti&Dia, our moissanite isn't limited to the classic round brilliant cut — we also offer an array of ultra-faceted, rarely seen shapes you may never have encountered before.