Red spinel is frequently mistaken for ruby, while we now have the scientific ability to easily tell the difference between the two gemstones, this was not always the case. Centuries ago upper class and royal individuals would use rubies to decorate their robes, ornaments and accessories, however, it has since been discovered that some gemstones used as rubies were in fact red spinel's.
Perhaps the most well-known and most sought-after spinel colour is the rich red spinel, however, these gemstones can also be found in a range of hues. Spinels can also occur in orange, pink, purple, and even blue, however blue spinels are extremely rare. The general reasoning behind the different colours spinels can come in is due to the traces and amounts of the three transition metals present in a spinels chemical composition.
Spinel was recently added as an August birthstone, sharing this month with peridot. It can also be used to celebrate the 22nd wedding anniversary.
Spinel is an oxide mineral and its chemical makeup includes elements magnesium and aluminium. In most cases spinel gemstones are more reflective and have a more glittery appearance than rubies, this makes their differences easier to distinguish to the untrained eye. Spinels also feature octahedral crystal forms (whereas rubies are more like hexagonal prisms). Sitting at a 7.5 to 8 on the Mohs hardness scale, spinels are relatively tough gemstones. It is a durable gemstone to use in jewellery creations, and with reasonable care can be worn daily.