Spinel is likely to have derived its name from the Greek word spinther which means spark or from the Latin word spina which means thorn. Spinel was often mistaken for corundum, sharing many of its most desirable properties: a striking spectrum of colors, high refractive index, lively fire and resistant hardness. The confusion was at times a genuine mistake but also intentional on occasion.
The mines of central and Southeast Asia produced large spinel crystals in the past. The ‘Black Prince’s ruby’ is a very famous spinel gemstone which is crimson-red in color. It is part of England’s Imperial State Crown which is situated in the Tower of London. The ‘Timur ruby’ that weighs over 350 carats is also a spinel in the Crown Jewels.
Spinel is mainly found in Burma, Vietnam, Tajikistan, Tanzania and Thailand.
The Spinel gemstone is found in varied colors and shades of the rainbow except for yellow. The different spinel colors are created when the quantities of magnesium or aluminium are modified. A whole gamut of red spinels is found, from blood red, brick red to rose red. The other colors that are available are orange, intense red, vibrant pink, and all shades of purple, blue, and violet including bluish green. The red, blue, pink and orange spinel is more in demand than the other colors.
Spinels that possess inclusions that are less visible are more valuable. There is a decrease in the value of spinel when inclusions are acutely visible. Inclusions that indicate spinel’s octahedral crystal growth appear quite beautiful to the eye. These are seen in clusters which are similar to fingerprints.
A variety of shapes and styles are created from spinel and the cushion and oval shapes are most popular.
The per carat price for spinel increases with size; red, pink, and blue stones above five carats are not easily available and larger ones are highly priced.