Sapphire is a very expensive and valuable gemstone that is of the mineral family corundum, composed of aluminum oxide (chemical formula: Al2O3). The sapphire in gemology is all gem-quality corundum, but not in red. Corundum with red color is distinguished as ruby.

Sapphires are valuable and robust types of gemstones in the world, and they are commonly utilized in classy jewelry and investment sectors.

Scientific and Mineralogical Characteristics of Sapphire

Sapphire has the following technical characteristics:

• Mineral Family: Corundum
• Chemical Composition: Aluminum Oxide (Al 2 O 3 ).
• Color: White, Colorless, Blue, Green, Yellow, Orange, brown, pink, Purple, Gray, Black, Multicolored.
• Crystal System: Trigonal
• Hardness: 9 on the Mohs scale
• Specific Gravity: 3.95 - 4.03
• Refractive Index: 1.762 - 1.770
• Transparency: Homogeneous to heterogeneous.
• Double Refraction: .0008
• Luster: Vitreous
• Cleavage: None

Sapphire is one of the hardest natural gemstones and unstable which makes it one of the strongest, and ranks second only to diamond.

Why Are Sapphires Blue?

Corundum in its pure state is naturally white. The traces of elements in the crystal structure give the sapphires their beautiful colors:

• Blue Sapphire: it is colored by iron (Fe) and titanium (Ti).
• Yellow Sapphire: This is caused by impurities of iron.
• Pink Sapphire: This is because of the traces of chromium.
• Green Sapphire: The product of mixed content of iron.
• Colorless Sapphire: Lacks color.

Blue sapphire is the most recognized and commercially important of all varieties. Our Natural Sapphire Collection is a broad collection of high-quality stones.

The Sapphire Geological Formation

The sapphires are formed inside the earth at high pressure and temperature. They are typically found in:

• Marble and schist are some of the metamorphic rocks.
• Basaltic igneous deposits
• Alluvial river gravels

The geological settings yield sapphires with their particular color and clarity features, so the origin is the factor that is of so great importance when it comes to the valuation of sapphires.

Major Sapphire Origins

The sapphires are mined in numerous regions of the globe, however, some of their sources are particularly renowned:

• Kashmir Sapphires - Fine, lavish blue, cornflower.
• Ceylon (Sri Lanka) Sapphires - bright and gleaming blue colors.
• Burma (Myanmar) Sapphire - Deep blue royalties.
• Madagascar Sapphires - Quality modern fine stones.
• Thailand and Tanzania - cheap sapphires of jewelry grade.

Provenience is a major determinant of the price and collectability of sapphires, particularly Kashmir and Ceylon sapphires.

Sapphire Colors

Though blue is the traditional sapphire color, sapphires are available in various forms of natural colors referred to as fancy sapphires. These include:

• Royal Blue Sapphires
• Cornflower Blue Sapphires
• Yellow Sapphires
• Pink Sapphires
• Green Sapphires
• White (Colorless) Sapphires
• Parti-colored Sapphires

No matter the color, all the non-red gemstones of corundum are technically considered sapphires.

Sapphire Varieties:

Color-Change Sapphire - Sapphire that displays another color under natural and artificial lights.

Cornflower Blue Sapphire - Characterizing Sapphire with a color that is cornflower-blue, which may be characterized as an intensive, velvety-blue color. The term is commonly used in conjunction with Kashmir Sapphire to signify the Sapphire of that area; it could also be used to refer to any Sapphire that has such color. The most desirable color in Sapphire is the cornflower blue.

Fancy Sapphire - The term used to refer to any Sapphire that does not have the color blue.

Kashmir Sapphire - Sapphire, of an intense, velvety-blue colour, in a Province of India, called Kashmir. Kashmir Sapphire is said to have the best color of all Sapphires.

Padparacha - Orange-pink Sapphire that is discovered in Sri Lanka; very popular and one of the most valuable forms of Sapphire.

Star Sapphire - Sapphire, which has been widely known as a star with six rays painted in the shape of a clear, six-rayed star. Star Sapphire is held in the highest esteem of all the gemstones that exhibit asterism.

Hardness and Durability

Sapphire is one of the hardest naturally available materials on earth, with a Mohs hardness of 9. This makes it:

• Very difficult to scratch.
• Perfect for everyday wear
• Best in engagement rings and heirloom jewelry.

One of the reasons why sapphires are so popular in fine jewelry is their durability.

Sapphire Treatments and Improvements.

Sapphire is typically heat-treated in order to deepen the blue colour and also eliminate inclusions in order to enhance clarity. Heat treating of Sapphire gemstones is a normal industry practice, and most of the Sapphires that are used as gemstones have undergone heat treatments. The unheated color of sapphire is significantly more valuable than the heat-treated one, and good gemstones are extremely expensive.

Sapphires are also treated to change color, and this is achieved using diffusion treatment, where the original stone changes color artificially. Diffused Sapphires colors are the deep blue color, bright yellow color, bright orange, and orange-red color. The diffusion is frequently carried out by heating a stone in a layer of beryllium metal. The diffused sapphire gems are relatively cheap in spite of their appealing color.

Due to all the quartz treatments and upgrades done to Sapphire gemstones, such details should always be made available to the consumer, and Sapphire must only be bought to high reputed dealers.

Natural Sapphires vs Treated Sapphires

Technically, the sapphires may be classified into:

• Natural Unheated Sapphires - Untreated, the rarest and most precious.
• Heated Sapphires - The color and the clarity are enhanced by heat.
• Diffusion or Enhanced Sapphires - Surface or lattice treatments.
• Synthetic Sapphires - The man-made corundum (not natural) is referred to as synthetic sapphires.

At Kashmir Stones, we have specialized on 100% natural sapphires and full disclosure on all the gemstones.

How Sapphires Are Graded

Sapphires like all other valuable gemstones are graded in terms of professional factors:

• Color: The value factor of highest importance.
• Transparency: Natural inclusions/ eye-clean look.
• Cut: Proportions and brilliance
• Carat Weight: Size and rarity
• Origin: The Kashmir and Ceylon origins are at premium prices.
• Status of the Treatment: Stones that are still unheated are the best.

Have a look at the graded and certified stones in our Loose Sapphire Gemstones Collection.

Uses of Sapphire

Technically Sapphires are also used due to their hardness and optical characteristics:

• Watch crystals
• Scientific instruments
• Industrial applications
• Luxury rings and engagement rings.

In jewelry use, our top-quality selection of Kashmir Sapphires and Ceylon Sapphires can be investigated.

Technical questions and answers about sapphires

Does Sapphire qualify as a mineral or a gemstone?

Sapphire is both. It is technically the mineral corundum and when it is of gem quality; it is a precious gemstone.

What are the chemical formulae of sapphire?

Sapphire has a chemical equation of Al2O3 (aluminum oxide).

What is the difference between sapphire and ruby?

Sapphire and ruby are both corundum. It only varies technically in the color whereby red corundum is referred to as ruby and any other color is known as sapphire.

Are all sapphires natural?

No. Sapphires may be natural, treated and synthetic. We are disclosing only natural sapphires that we sell.

Which is the most difficult gemstone after diamond?

The hardest gemstones in nature (after diamond) are sapphire and ruby, having Mohs hardness of 9.

What origin of sapphires is the most valuable?

Kashmir sapphires are regarded as the precious spring, then the Ceylon sapphires of the high quality, and Burma sapphires.

Is it possible to wear sapphires daily?

Yes. Sapphires are very tough and are therefore durable and can be used in ordinary jewelry like engagement rings.

Conclusion: The Contemporary Viability of Sapphire

Sapphire is one of the most stunning inventions of nature--a crystal of aluminum oxide which is changed with the help of the trace elements into the rainbow of arresting colors. Being characterized by unusual hardness and brilliance as well as resistance, sapphire is second to diamond in toughness, which is why it is not only a marvel of science but also a classic image of grace.

Sapphires are products of the special geological conditions that confer their beauty on them, whether of the velvety blues of Kashmir or the brilliant radiance of Ceylon. They are also priced depending on their color and clarity and origin and history of treatment with natural, unheated stones being the most prestigious.