September Birthstone: Sapphire
Alongside diamond, ruby, and emerald, sapphire is one of the “big four” precious gemstones. Famous for its striking deep blue color, sapphire actually occurs in an extraordinary range of hues, from colorless, pink, and orange, to green, purple, brown, and black. Its classic blue is so iconic that sapphire has long served as a standard of comparison for the color of other blue gemstones, including topaz and tanzanite.
Treasured for thousands of years as a symbol of truth, loyalty, and protection, this remarkable gemstone has found its place everywhere from ancient legends and royal treasures to engagement rings and meaningful birthstone jewelry. As both the modern and traditional September birthstone, sapphire has a rich history, fascinating range of colors, and enduring symbolism that make it a gemstone well worth exploring.
Origin of the Name
The name “sapphire” has ancient roots, ultimately deriving from the Greek word sappheiros and the Latin sapphirus. These terms were historically associated with lapis lazuli and other blue stones rather than exclusively referring to the gemstone we know as sapphire today. Over time, the name came to be associated specifically with sapphire.
What Is Sapphire?
Sapphire is a precious gemstone and a variety of corundum, a crystalline form of aluminum oxide. Both sapphire and ruby are varieties of the mineral corundum: red gem-quality corundum is classified as ruby, while gem-quality corundum of other colors is considered sapphire. In its pure form, corundum is colorless, while trace elements within the crystal produce the many colors found in sapphires. The classic blue for which sapphire is best known results primarily from the presence of iron and titanium.
With a hardness of 9 on the Mohs scale, sapphire is one of the hardest naturally occurring minerals, second only to diamond among the traditional gemstones. Its exceptional durability makes sapphire particularly well suited to jewelry, including pieces intended for frequent or everyday wear.
Blue, Fancy & Beyond: The Many Colors of Sapphire
From left to right: Blue sapphire (source), purple sapphire (source), pink sapphire (source), and yellow sapphire (source).
Although the word “sapphire” on its own usually brings the classic blue variety to mind, sapphires can also be pink, yellow, orange, green, purple, gray, brown, black, and even colorless (also referred to as white). Sapphires in colors other than blue are commonly known as “fancy sapphires".
Ruby or Pink Sapphire?
The boundary between ruby and pink sapphire isn't always clear-cut. Color classifications can vary within the gem trade and between cultures. The Gemological Institute of America (GIA) classifies a stone as ruby when red is its dominant hue; lighter or less distinctly red corundum may instead be classified as pink sapphire.
Multi-Colored Sapphires
Some sapphires display more than one color within a single stone. Known as “parti-colored” or “parti sapphires", these gemstones often feature distinct areas of two or more colors, such as blue and yellow or green and yellow. Australia in particular is well-known for producing striking parti-colored sapphires.
Lotus Blossom Sapphires
Among the rarest and most celebrated fancy sapphires is the "padparadscha", prized for its distinctive blend of pink and orange. Its name comes from a Sinhalese word associated with the lotus blossom, whose delicate color the gemstone is said to resemble.
Star Sapphires
Sapphires can also exhibit unusual optical phenomena. Tiny, oriented inclusions within some stones create a star-like pattern called asterism, producing what is known as a “star sapphire". The effect typically appears as a six-rayed star across the surface of a cabochon-cut gemstone.
Color-Changing Sapphires
Some sapphires change color depending on the type of light in which they are viewed, a phenomenon famously associated with alexandrite. While the exact colors can vary, a typical color-change sapphire appears blue to violet in daylight or fluorescent light and shifts toward violet or reddish purple under incandescent light.
Sapphire in Ancient & Medieval Cultures
For thousands of years, sapphire has been surrounded by symbolism, folklore, and beliefs about its protective and even mystical powers. Although these traditions varied between cultures and time periods, sapphire was repeatedly associated with the heavens, protection, truth, and the divine.
According to ancient Persian belief, the earth rested upon an enormous sapphire whose reflection gave the sky its blue color. In ancient Greece and Rome, members of the elite believed that blue sapphires could protect their owners from envy and harm.
Sapphire's association with the divine continued into the Middle Ages. Clergy wore blue sapphires as a symbol of Heaven, while others believed the gemstone could attract heavenly blessings. Medieval Europeans also attributed healing properties to sapphire, believing that it could treat diseases of the eye and even serve as an antidote to poison.
Across different periods and traditions, sapphire acquired an extraordinary range of other reputed powers. It was said to guard chastity, promote peace between enemies, influence spirits, and help reveal hidden truths or the secrets of oracles.
Though the mystical and healing properties once attributed to the stone are rooted in tradition and folklore rather than scientific evidence, these stories offer a fascinating glimpse into the meaning sapphire has held across different cultures and time periods. It is also worth remembering that ancient gemstone classifications differed from those we use today, so some historical references to sapphire may actually describe other blue stones, particularly lapis lazuli.
From Royalty to Romance: Sapphire in Modern Jewelry & Culture
Sapphire's centuries-old associations with royalty, faithfulness, and romance continue to influence the way the gemstone is worn today. Its beauty and exceptional durability have made it a popular choice for fine jewelry of all kinds, including engagement rings.
Replica of Princess Diana's engagement ring.
Source
Perhaps the most famous modern example is the blue sapphire engagement ring once worn by Princess Diana. Featuring a 12-carat oval blue sapphire surrounded by diamonds, the ring was originally presented to Diana by Prince Charles in 1981. Nearly three decades later, their son Prince William gave the ring to Catherine Middleton upon their engagement in 2010, introducing the iconic sapphire to a new generation.
The Logan Sapphire.
Source
Other celebrated sapphires include the Logan Sapphire, a 423-carat Sri Lankan sapphire and one of the world's largest faceted blue sapphires, now housed in the Smithsonian's National Gem Collection. The 62.02-carat Rockefeller Sapphire, originally acquired by John D. Rockefeller, Jr. from an Indian maharaja in 1934, is another of the world's most famous examples.
Beyond its royal and historical connections, sapphire holds special significance as the birthstone for September and the traditional gemstone commemorating both the 5th and 45th wedding anniversaries. Whether chosen for its symbolism, its remarkable range of colors, or simply its beauty, sapphire remains one of the world's most enduring and versatile gemstones.
Sapphire Symbolism & Meaning
Throughout its long history, sapphire has accumulated a rich variety of meanings. Its traditional associations with the sky and heavens have linked the gemstone with divinity, wisdom, truth, and clarity, while centuries of use by royalty and religious figures have made it a symbol of nobility, faith, and protection.
Sapphire also has longstanding associations with sincerity and faithfulness. Today, these qualities give the gemstone particular significance in romantic jewelry, where it can symbolize loyalty, commitment, and enduring love—one reason sapphire has remained a meaningful alternative to diamond for engagement rings.
As both the modern and traditional birthstone for September, sapphire can hold an additional personal meaning for those born during the month. Whether chosen for its history and symbolism, its connection to a loved one, or simply its beauty, sapphire has remained a meaningful gemstone across cultures and generations.
Sapphire Gemstone Properties
Mohs hardness: 9
The Mohs hardness scale measures a gemstone's resistance to scratching, on a scale from 1 (very soft) to 10 (very hard). Sapphire ranks 9 on the Mohs scale, making it one of the hardest naturally occurring minerals. Only diamond, at 10, ranks higher among commonly used gemstones.
This exceptional hardness is one reason sapphire is so well suited to jewelry. It resists everyday scratches and abrasion better than many other colored gemstones, making it an especially practical choice for frequently worn pieces such as rings.
Refractive index: 1.762–1.770
Refractive index (RI) measures how much light slows down and bends as it enters a material. Sapphire has a relatively high refractive index of approximately 1.762 to 1.770, which allows it to bend and reflect a significant amount of light, contributing to the bright, lively appearance of a well-cut stone.
Sapphire is also doubly refractive, or birefringent, meaning that light entering the stone can split into two rays traveling at slightly different speeds. Its birefringence is relatively low, approximately 0.008 to 0.010, so the effect is generally much less noticeable than in strongly birefringent gemstones.
Luster: Vitreous (glass-like)
Luster describes how a gemstone's surface reflects light. A polished sapphire typically displays a vitreous, or glass-like, luster, giving its surface a bright, smooth sheen.
Combined with sapphire's rich color and ability to take a high polish, this luster contributes to the gemstone's distinctive appearance and makes both blue and fancy-color sapphires especially striking when faceted.
Specific gravity: Approximately 4.00
Specific gravity compares a gemstone's density with that of an equal volume of water. Sapphire has a specific gravity of approximately 4.00, meaning it is relatively dense for a gemstone.
This also means that two gemstones of the same carat weight can have noticeably different dimensions depending on their mineral composition. A sapphire may appear smaller than a less-dense gemstone of the same weight because more of its mass is concentrated within a smaller volume.
Natural vs. Lab-Grown Sapphire
Sapphires can be either natural or lab-grown. Natural sapphires form within the earth over millions of years, while lab-grown sapphires are created under controlled conditions that replicate the processes necessary for sapphire crystals to form.
Unlike sapphire imitations, lab-grown sapphires are real sapphires. They share the same chemical composition and crystal structure as their natural counterparts, along with sapphire's exceptional hardness and durability. The primary difference is their origin.
At Close By Me, we use lab-grown sapphires by default in our birthstone jewelry. Their beauty, durability, and consistency make them especially well suited to our designs while allowing us to offer sapphire jewelry at a more accessible price. Natural sapphires may also be available by special request for those who prefer a naturally formed gemstone.
How to Wear & Care for Sapphire Jewelry
With a hardness of 9 on the Mohs scale, excellent toughness, and no cleavage (natural weak points along which a gemstone can split), sapphire is exceptionally well suited to jewelry. Its resistance to scratching makes it a particularly practical choice for rings and other pieces worn frequently or even daily.
Despite its durability, sapphire jewelry still benefits from proper care. Like any gemstone, sapphire can be chipped or damaged by a sufficiently hard impact, and the precious metal and settings surrounding the stone may be more vulnerable than the sapphire itself.
Gentle cleaning: warm water + mild soap
The safest way to clean sapphire jewelry at home is with warm water, mild dish soap, and a soft toothbrush or cloth. Gently clean around the gemstone and setting to remove oils, lotions, and everyday buildup, then rinse thoroughly and dry with a soft, lint-free cloth.
Avoid harsh chemicals
Sapphire itself is resistant to many common chemicals, but the metals and other materials in a finished piece of jewelry may not be. Chlorine, bleach, household cleaners, and other harsh chemicals can damage or discolor precious metals over time.
For this reason, it's best to remove sapphire jewelry before swimming in chlorinated pools or cleaning with household chemicals.
Avoid mechanical cleaning methods
Untreated and heat-treated sapphires can generally withstand ultrasonic and steam cleaning, but these methods aren't appropriate for every sapphire or every piece of jewelry. Powerful vibrations or high heat may affect certain gemstone treatments or place unnecessary stress on stone settings over time.
For this reason, gentle hand cleaning remains the safest approach for preserving both the sapphire and its setting.
Safe storage & daily wear
Although sapphire is highly resistant to scratching, its hardness also means it can scratch softer gemstones and metals stored alongside it. Keep sapphire jewelry in a soft pouch or separate compartment of a jewelry box when it isn't being worn.
Remove your jewelry before heavy lifting, sports, yard work, or other activities that could expose the gemstone and surrounding metal to a hard impact. With mindful wear and routine care, sapphire is an excellent choice for jewelry designed to be cherished for many years.
Sapphire in Birthstone & Meaningful Jewelry
With its associations with loyalty, sincerity, truth, and enduring love, sapphire can bring special meaning to jewelry chosen to represent someone important. For those born in September, the gemstone also carries the personal significance of their birth month, whether worn to represent yourself or someone you love.
At Close By Me, sapphire is featured throughout our birthstone jewelry collection, where it can add a personal touch to a piece chosen for its beauty, symbolism, or connection to a September birthday. While blue is the traditional September birthstone color, other sapphire colors may be available by request.
The Enduring Appeal of Sapphire
From ancient beliefs about the heavens to some of the world's most celebrated royal jewels, sapphire has carried meaning across cultures and generations. Its exceptional durability, remarkable range of colors, and longstanding associations with loyalty, sincerity, and enduring love have helped make it a gemstone that feels just as relevant today as it did centuries ago.
For those born in September, sapphire offers an especially personal connection as the month's only official birthstone—but a gemstone doesn't need to represent your own birth month to hold meaning. Whether chosen to celebrate yourself, represent someone you love, or add another layer of significance to a memorial piece, sapphire can serve as a beautiful and lasting reminder of the connections that matter most.
Sources:
This birthstone guide was researched using trusted gemological, historical, and educational references, including:
- American Gem Society (AGS)
- Gemological Institute of America (GIA)
-
International Gem Society (IGS)
- Selected historical and cultural sources
Including classical writings and widely documented folklore referenced through reputable gemological summaries.
