Purple Spinel Rectangular Cushion Cut 1.5ct

Spinel is a magnesium-aluminium oxide, crystallised in cubic system and usually found in octahedral crystals. It forms in metamorphic limestone most of the time. Often found alongside corundum (ruby&sapphire) deposits. With a hardness of 8 on Mohs scale, spinel is well suited for all jewellery applications. Although not as rare as ruby, it is hard to come by in sizes over 5ct.
Pure spinel is colourless. All of its many hues come from trace elements present in its structure and include shades of red, purple, pink, orange, blue and even black. There are many new sources of attractive looking spinels. Just one of the reasons why spinels grow in popularity nowadays. Extremely rare, cobalt coloured, blue stones of Luc Yen in Vietnam. Neon glowing red Jedi Spinels of Mogok, Burma. Also, hot pink-red variety coming from Mahenge in Tanzania. Other notable sources include Madagascar and Sri Lanka.

Spinel is not commonly treated but there have been reports of heat treatment being applied more often in recent times. Synthetic stones; however, are fairly common and made in a variety of colours, often to imitate other gems. A trained gemologist should have no problem in recognising those.