Moissanite is gem grade silicone-carbide, the second hardest substance known to man after diamond (although it is man-made, unlike sapphire). In recent years it has become another more affordable, ethical alternative to diamonds, however the colour isn’t as good and can often look a little yellow.
Sapphires and rubies are both a gemstone variety of the mineral corundum. Rubies are always red whereas sapphires come in a huge variety of colours, such as blue, yellow, purple, pink, orange and green. Corundum is the next hardest naturally occurring substance after diamond, making it very suitable for using in rings that are going to be worn for a long time.
Lab grown sapphires are also available, and are an astonishingly beautiful colour at a very low price. We find people often feel that lab grown hasn’t got quite the romance of mined, though.
Tanzanite isn’t quite as hard as we’d like for engagement rings, but as it is such a beautiful colour, it does get requested fairly regularly. It is found only in Mererani Hills of Manyara Region in Northern Tanzania.
Emerald the most commonly known variety of the mineral beryl. It is fairly soft compared to diamonds and sapphires so we tend to recommend well-protected settings for engagement rings. Emeralds are readily available but to get a lovely clear stone with a good deep colour, the prices can be comparable to diamonds.
Lab grown emeralds are also available, and have a beautiful clear deep green colour.