Gem School - Gemology School - Gemologist School

THE STONES POPULARLY KNOWN AS RUBY AND SAPPHIRE

are actually the same mineral, known scientifically as corundum. Their crystal properties are the same. In fact the major difference is their colour, which is caused by small amounts of colour causing elements like chromium in ruby and iron and titanium in blue sapphire.

Gemstones

Ruby

Ruby

Known throughout history as the stone of kings, ruby is the red variety of corundum. Ruby also holds the record for being the most valuable gemstone by weight.

Sapphire

Sapphire

The blue variety of corundum, sapphire, has been associated since time immemorial with power, both in the nobility, and in the church.

PADPARADSCHA

PADPARADSCHA

Arguably the most popular “fancy sapphire,” this blend of pink-orange and its closeness to the lotus flower bloom is what earned this variety of sapphire its name.

FANCY SAPPHIRE

FANCY SAPPHIRE

"Fancy sapphires" encompasses all sapphire varieties except for blue and red. They are typically identified by their specific hue, such as yellow sapphire.

CORUNDUM SOURCE

MYANMAR

For several centuries the most famous ruby producing region.

MOZAMBIQUE

A major producer of modern rubies. The strong and steady supply of high clarity, evenly colored ruby has quickly made it an important and popular source.

MADAGASCAR

One of the youngest and strongest producing sapphire deposits. The complex geological conditions of madagascar have produced a large variety of exceptional and unique sapphires.

SRI LANKA

Formerly known as Ceylon, many of history's royal sapphires are mined here.

AUSTRALIA

A modern heavy-weight for many parti-coloured sapphires and fancy blue-green-yellow sapphires.

OTHERS

The world is large, and new deposits are still being explored. New ruby production has even been found in the frozen island of Greenland.

TREATMENTS HEATING

Few of the world's corundum come out of the ground looking like the stone of our dreams. This rarity is part of what makes corundum an excellent asset and object of distinction. In order to meet market demands for jewelry, clever individuals found ways to mimic natural geological processes. These processes can in some cases cause the gemstones' component elements to unlock and recombine in a way that improves the beauty of the stone.

Other more complex heat treatments of corundum also exist and a shrewd buyer will confirm the identity and treatment status of the stone with a reputable gemological laboratory.

AITREATMENTS Glass Filling

Lead-glass Filled: Pb or Bi Blue Flash Effect in Ruby

Lead-glass Filled: Pb or Bi Gas Bubbles in Blue Sapphire

A common sight in many tourist shops, glass-filled corundum is available often as large pieces of low quality ruby and sapphire. This product takes the plentiful otherwise unusable corundum gravels and fills in all of the cracks and flaws with a mixture of glass, additives and even sometimes extra colorants. This process can produce large pieces of affordable “ruby” or “sapphire” with a bold, eye-catching appearance. The original stone material is earth mined, but the final product is so abundant and easily produced that its value is far lower than untreated or traditionally heated corundum. To an experienced buyer, this treatment is easy to identify with a 10x loupe, and vendors that value their reputation must disclose this treatment clearly.

Lead-glass Filled Rub

TRADE TERMS OF COLOR

PIGEON’S BLOOD

historical name used with a unique color of truest and brightest red Burmese rubies. Now it is used internationally

CORNFLOWER BLUE

Named after the hue of the cornflower, this fresh and youthful blue is one of the most sought after

ROYAL BLUE

A deep and bold blue color that has been associated with history's royal houses.

BUYING TIPS

COLOR

An eye pleasing color in all lighting conditions is the key to a top quality sapphire. View the stone indoors and outdoors at different times of day if possible to ensure that the stone is the right fit for you and your uses. Almost any stone looks great in direct sunlight. Will yours look excellent at that candlelit dinner tonight?

CUTTING

High quality sapphire crystals are immensely rare in nature. This in turn often leads to less precise cutting of the crystal to preserve the original weight and color at its maximum. Precision cut sapphires will come at a premium price.

CLARITY

Gemstones are not glass, and as such we can expect some natural flaws or inclusions to be present in the stone. The clearer a stone, the higher the price, but beware the stone with no inclusions. Be sure to double check with a reputable lab to protect your investment from a stone that is too good to be true.

CARAT

The formation of corundum in nature does not often produce perfect crystals. Often a large part of a larger original crystal is unattractive and must be cut away to yield a beautiful gem. Larger, high quality crystals necessary to cut perfect large gems are exceedingly difficult to find, and the price follows that rarity.

DID YOU KNOW ?

Ruby must have a dominant red hue. Corundum that has too low of a saturation of red, or tends too far towards pink or purple may end up being referred to as a pink or purple sapphire by reputable labs

Ruby VS

Pink Sapphire

THE WORLD'S MOST EXPENSIVE RUBIES (AS OF 2026)

The Estrela de Fura — $34.8 Million

Weight: 55.22 carats

Origin: Montepuez, Mozambique

Shape: Cushion

Cut: Mixed cut

Sold: June 2023, Sotheby’s New York

Key Detail:
Currently the world record holder for any ruby sold at auction, the Estrela de Fura repzresents a historic breakthrough for Mozambique rubies. Its exceptional size and quality have significantly elevated the global standing of African-origin rubies, which were once considered secondary to Burmese stones.

Source: Sotheby’s – Estrela de Fura

Photo Credit: Prestige Online

The Sunrise Ruby — $30.4 Million

Weight: 25.59 carats

Origin: Mogok, Myanmar (Burma)

Shape: Cushion

Cut: Mixed cut

Sold: May 2015, Sotheby’s Geneva

Key Detail:
An outstanding example of an unheated “pigeon’s blood” ruby, the Sunrise Ruby remains one of the most celebrated gemstones ever auctioned. Mounted by Cartier, it achieved a remarkable price per carat exceeding $1.18 million, setting a global benchmark for fine Burmese rubies.

Source: Sotheby’s – The Sunrise Ruby

Photo Credit: High Jewellery Dream

The Crimson Flame — $18.3 Million

Weight: 15.04 carats

Origin: Myanmar (Burma)

Shape: Cushion

Cut: Mixed cut

Sold: December 2015, Christie’s Hong Kong

Key Detail:
Renowned for its vivid saturation and exceptional transparency, the Crimson Flame achieved approximately $1.21 million per carat, briefly surpassing the Sunrise Ruby in per-carat value. This highlights the critical role of color purity and crystal quality in determining value.

Source: Christie’s – The Crimson Flame

Photo Credit: © Christie’s Images Ltd.

The Jubilee Ruby — $14.16 Million

Weight: 15.99 carats

Origin: Mogok, Myanmar (Burma)

Shape: Oval

Cut: Mixed cut

Sold: April 2016, Christie’s New York

Key Detail:
An unheated oval-cut ruby, set in a distinctive mount by Verdura in 18k gold and platinum. At the time of its sale, it became the most expensive colored gemstone ever auctioned in the United States, reinforcing the strength of the U.S. collector market.

Source: Christie’s – The Jubilee Ruby

Photo Credit: The Jewellery Editor

The Etcetera Ruby — $13 Million

Weight: 120.74 carats (48 rubies)

Origin: Mogok, Myanmar (Burma)

Shape: Oval and cushion-shaped rubies

Cut: Mixed cut

Sold: June 2, 2015, Christie’s Hong Kong

Key Detail:
Designed by Edmond Chin for Etcetera, this exceptional necklace features 48 unheated “pigeon’s blood” rubies set within an intricate lattice of brilliant-cut diamonds.
It is regarded as one of the most important ruby jewelry creations ever brought to auction and held the world record for a ruby necklace for several years, highlighting the rarity of assembling a matched suite of top-quality Burmese rubies.

Source: Christie’s – A Magnificent Ruby and Diamond Necklace by Etcetera

Photo Credit: © Christie’s Images Ltd.

The world record was set for the highest price of a gemstone by weight in 2016, when a 25.59 carat Burmese ruby ring was sold for over 30 million U.S. dollars.