The September birthstone is sapphire, which is well known for its beautiful blue color. However, sapphires come in a variety of colors beyond blue. While blue is the most common and classic color for September’s birthstone, sapphires can range from pink, yellow, green, orange, purple, and more. So is September’s birthstone always blue? Let’s take a closer look at sapphire colors and what makes September’s birthstone blue or not.
What is a Sapphire?
Sapphire is a precious gemstone that is a variety of the mineral corundum. Corundum itself is colorless, but trace elements within it produce various colors. The mineral aluminum oxide causes corundum to form hexagonal crystals that make up sapphire’s structure. When chromium is present, it produces the classic blue sapphire, but other elements result in different hues.
Blue Sapphire Colors
The most prized and valuable shade of sapphire is a deep, rich cornflower blue, known as Kashmir blue. These sapphires from Kashmir, India exhibit a velvety hue with a subtle violet undertone. Burmese blue sapphires also display a highly coveted color, with a pure royal blue that has high saturation. Sapphires from Sri Lanka typically have lighter, brighter blues.
While most blue sapphires have some secondary hues, the most valuable have a pure primary blue without any overtones. This saturateed medium to medium-dark blue is considered classic, especially for September birthstones. The exact tone can range from a light sky blue to rich navy.
What Makes Sapphires Blue
Trace amounts of chromium cause the blue color in sapphires. Chromium is a chemical element that when present in small amounts produces brilliant blues. The chromium ions absorb certain wavelengths of light, while reflecting blue wavelengths back to our eye, creating the blue color we see.
The chromium must be in the right oxidation state and concentration to produce the blue hues. Too much chromium can make the stone appear inky. Without any chromium, sapphires appear colorless or exhibit other colors, but not blue.
Other Sapphire Colors
While blue is most common, sapphires come in a full spectrum of colors:
Pink – Trace amounts of chromium paired with titanium result in pink sapphires. Padparadscha sapphires are an orangey pink variety highly prized for their uniqueness and rarity.
Yellow – When iron and titanium impurities are present, yellow sapphires form. Fancy yellow sapphires are rare and valuable.
Green – Trace iron within the corundum is responsible for green sapphires. Medium to deep green colors are the most desired.
Orange – A mix of chromium and iron makes sapphires orange. Most orange sapphires are pale, with deep orange being extremely uncommon.
Purple – A blend of iron and titanium produces purple sapphires.
White – Very pure sapphires that lack impurities appear white.
Black – When iron and titanium impurities heavily concentrate in areas of the stone, opaque black zones emerge on some sapphires.
Are Black Sapphires Really Sapphires?
Black sapphires are still real sapphires, even though they lack the color we typically associate with the gemstone. They fall within the spectrum of what makes a sapphire – a blue corundum. The black zones are caused by inclusions of dark minerals. When cut correctly, the black areas contrast beautifully with the blue, creating a striking color change sapphire.
Padparadscha – The Rarest Sapphire
Some consider padparadscha to be the rarest and most valuable sapphire variety. Padparadscha exhibits a beautiful salmon color that is a mix of pink and orange. The delicate hue resembles a lotus flower and comes from a Sinhalese word meaning “lotus flower color”. Only about one out of every 10,000 sapphires exhibits this exceptional shade.
Are Colorless Sapphires Still Sapphires?
Yes, a colorless or white sapphire is still a true sapphire. As mentioned earlier, pure corundum is actually colorless. Color is only introduced when trace elements and impurities are present. So a sapphire without any impurities will form as a clear, transparent gem. These are sometimes called Leukosapphire, but they meet the mineralogical definition of a sapphire.
Which Sapphire Colors Are Most Rare?
Here is a ranking of some of the rarest and most valuable sapphire colors:
1. Padparadscha – The orangey-pink sapphire is the rarest of all
2. Pure Blue – Deep, vivid blues are especially rare
3. Certain Shades of Yellow – Fancy yellows are uncommon
4. Bright Greens – Vivid green is rare compared to blue shades
5. Natural Star Sapphires – Only about 1% exhibit the star effect
Are Sapphires Only Blue in September Birthstones?
While the September birthstone is historically linked to blue sapphire, all sapphire colors are appropriate for September birthdays. September babies are lucky to have such an array of hues to choose from. Jewelry stores sell sapphire birthstone gifts in blue as well as pink, yellow, orange, green, and purple.
The blue sapphire may be the most traditional, but there’s no rule that says September birthstones must be blue. Sapphires naturally form in a full spectrum of colors thanks to varied trace elements. Any sapphire color can make a meaningful, beautiful September birthstone.
Birthstones By Month
| Month | Birthstone |
|---|---|
| January | Garnet |
| February | Amethyst |
| March | Aquamarine |
| April | Diamond |
| May | Emerald |
| June | Pearl, Moonstone |
| July | Ruby |
| August | Peridot |
| September | Sapphire |
| October | Opal, Tourmaline |
| November | Topaz, Citrine |
| December | Tanzanite, Turquoise, Zircon |
Conclusion
In summary, while blue is the most classic sapphire color, September’s birthstone comes in every color of the rainbow. Sapphires naturally form in various hues based on trace impurities within the mineral corundum. So September babies are lucky to be able to pick a sapphire birthstone ranging from blue to pink, yellow, green, orange, purple, and more. While the blue sapphire remains popular for its beauty and symbolism, those born in September have options for their meaningful gemstone. Sapphire gives September babies a spectrum of birthstone choices.
Summary
– The September birthstone is sapphire, most known for its blue color.
– Sapphire’s classic blue color comes from trace amounts of chromium within the mineral corundum.
– Without chromium, sapphires form in other colors like pink, yellow, green, orange, purple, and even white or black.
– Padparadscha sapphires are the rarest and most valuable for their soft orange-pink color.
– Blue is the most traditional September birthstone color, but sapphires in any hue are suitable.
– September babies are lucky to have so many color options to find the perfect sapphire birthstone.
Conclusion
While sapphires are famous for their striking blue hues, the September birthstone occurs naturally in a full spectrum of colors. Sapphire color depends on trace impurities within the corundum mineral. Blue sapphires get their color from chromium, but other elements result in other colors like pink, yellow, green, orange, and purple. While the blue sapphire remains the most classic, those born in September are fortunate to have so many options for this varied birthstone. Any sapphire color can hold meaning and make a cherished September birthstone. Sapphire gives September babies a rainbow of birthstone choices.
