Ruby belongs to the corundum family of which all except red are known as sapphires, rubies and so sapphires have similar properties.
It is a gem highly valued for their rarity, since the mines are almost exhausted in the world and there is little production with good qualities, especially in large sizes.
In May 1995, a ring with a ruby of 16 carats was sold for 4 dollars millos auction house Sotheby's in Geneva.
- Hardness: 9 Mohs
- Specific Gravity: 3.9 to 4.1
- Conchoidal fracture
- Color: Deep red to purple or brown
- Vitreous luster, and occasionally it may seem silky
- Variable transparency, and possible presence of inclusions that give a milky appearance.
Ruby producing countries
First a clarification, because we have to differentiate between source and origin.
Country of origin means the mine and origin is where it is marketed and handled is. For example we can have a ruby whose origin is a mine in Vietnam and its origin is Thailand because it is here that has been carved and sold.
Thailand is the country of marketing size and rubies in the world, but just have a few small mines in Chantaburi. The main deposits of the world are on Burma (Myanmar); Sry Lanka; Vietnam, Cambodia; Madagascar and Mozambique.
Rate a ruby
Rubies are valued based on their color, clarity, cut and size.
- Color: Unlike the diamond, there is a color scale (only orientative GIA scale), so there is great about subjectivity. In principle rubies with a slightly dark but transparent deep red called "pigeon blood" would be the most valuable color, and when I have violet tones, it loses value.
As the degree of color intensifies the stone loses transparency, so we must seek an intermediate between the intense color and transparency. The light must pass enough but at the same time allow an intense color.
It is important the lighting used to see the ruby. Sunlight fluorescence is superior and ruby red appears. It is said that the ruby is a gemstone at night because it looks very red in incandescent light.
To purchase, the sun should not give fully into the stone. If low light is red, it is because it has good color.
- Purity: As for the purity we say that to be the scarcest ruby inclusions devalue it less than in other gemstones, although certainly the fewer there and purer the ruby will also be more valuable.
- Size: Rubies usually occur in oval or emerald cut. However large round cut rubies are generally more expensive because more material is wasted.
- Weight: The most valuable gems are usually between 3 and 5 carats in weight, although the law of supply and demand prevails in this case. From these weights the price is very subjective and can be very high.
It is a 167 carat Burmese ruby donated by John Ruskin the British Museum of Natural Science.
Roser Reeves ruby:
A breathtaking ruby with effect from Sri Lanka weight of 138 carats star, and is currently owned by the Smithsonian Museum in Washington.