Ruby

RaffaelloSanzio: Portrait of Maddalena Doni

The name Ruby comes from the Latin Ruber, which means “red”. Medieval Europeans wore ruby to succeed in Love, health and wealth.  Because of its color has always been associated with passion, love and beauty. It is the world most famous and best-loved red gem. 

 

Is the most important colored stone in the market and is the red variety of the gem species Corundum. 

The quality of a ruby is determined by different factors, the most important is the color.  The finest Ruby has a vivid red color with a light purple hint. In its purest form, the corundum is colorless, but if some trace elements stick into the crystal’s structure, the mineral can have some change in color. In the case of Ruby, the trace element that affects the red color is the Chromium. The saturation of the color depends of the quantity of Chromium present in the Corundum.  Because the Chromium causes fluorescence, the best ruby must have also some traces of Iron, which inhibits the fluorescence. 

Its hardness is 9 on the Mohs scale, is the hardest stone on Earth after the Diamond.

Historically the best quality color ruby comes from the Burmese source, which is described as “pigeon’s blood”.  Even though the origin of a Ruby is important to guarantee the quality, not only Myanmar produces high quality gems, any ruby source can produce both high and low quality stones.

The major sources of Ruby are in Asia: Myanmar, Thailand, Sri Lanka, Cambodia, and Pakistan.

 

There are mines also in Africa: Madagascar, Kenya, Malawi and Tanzania.

 

Natural Rubies are very often included, and is also difficult find it in big specimen. It’s rare see an eye clean ruby in exceptional size.  The environment where the ruby forms makes it difficult, for the crystal, to grow.

But the story is different for the sapphire, the brother of Ruby; the blue stone is easily found in bigger size and less included.

 

Treatments are widely used to enhance the beauty of the Ruby, and the heat treatment is now so common that is accepted in the trade, actually in every gem market it is assumed that all rubies are heated, unless there is a certificated that can prove it. Heat has multiple benefits; it works in both color and clarity. Any brown shades, that lower the quality, disappear to bring out the red color; while also the inclusions become less visible. Other used treatments, less accepted from the trade, are dyeing and fracture filling. 

Can happen sometimes, to see in the market the star ruby, the phenomena, called asterism,  is caused by the needle-like inclusions into the stone, if is cut into a cabochon the light is reflected in a 6-rays star. Those gems are highly priced and very rare.

Ruby and star ruby are both the US birthstones of July.

Ruby is one of the earliest colored stones to be imitated, with both natural and synthetic materials.  Glass is the most common material used as imitator. Other material are: red spinel, garnet, CZ, and dyed corundum.

Red Spinel

 

Garnet

 

CZ - Cubic Zirconia

In late 19teen century, some scientist introduced in the market a new kind of rubies manmade in lab. They found the way to synthesize in the lab what Mother Nature makes in million years. The process is quick and cheap.  Those synthetic rubies are now easily affordable, not expensive and look really good to the untrained eye. But don’t worries, the gemologist has the knowledge to distinguish between those and a natural one, if you want to buy a jewel with Ruby, always ask for a certificated, just to be sure!