The September birthstone is the Sapphire. Blue sapphire belongs to the mineral species corundum. It can be a pure blue but ranges from greenish blue to violetish blue. The name “sapphire” can also apply to any corundum that’s not red and doesn’t qualify as ruby (another corundum variety).
Besides blue sapphire and ruby, the corundum family also includes so-called “fancy sapphires.” They come in violet, green, yellow, orange, pink, purple, and intermediate hues. Sapphires can even be gray or brown.
Fancy sapphires are generally less available than blue ones, and some colors are scarce, especially in very small or very large sizes. Still, fancy sapphires create a rainbow of options for people who like the romance associated with this gem, but who also want something out of the ordinary.
The mineral corundum is composed only of aluminum and oxygen, and it requires a growth environment that’s free of silicon. However, silicon is a very common element, making natural corundum relatively uncommon. In its purest state, corundum is actually colorless, but this is very rare. Most corundum contains color-causing trace elements. When the trace elements are iron and titanium, the corundum is blue sapphire. Only a few hundredths of a percent of iron and titanium can cause the color, and the more iron the corundum contains, the darker the blue. Chromium can cause the red color of ruby or the pink of pink sapphire.
Both blue and fancy sapphires come from a variety of exotic sources including Madagascar, Tanzania, Sri Lanka, Myanmar, and Australia.
Traditionally, sapphire symbolizes nobility, truth, sincerity, and faithfulness. It has decorated the robes of royalty and clergy members for centuries. Its extraordinary color is the standard against which other blue gems—from topaz to tanzanite—are measured.
In ancient Greece and Rome, kings and queens were convinced that blue sapphires protected their owners from envy and harm. During the Middle Ages, the clergy wore blue sapphires to symbolize Heaven, and ordinary folks thought the gem attracted heavenly blessings. In other times and places, people instilled sapphires with the power to make peace between enemies, influence spirits, and reveal the secrets of oracles.