Taaffeite is very rare, and is unique in being the only gemstone not recognized as a new mineral species until it had been faceted. The first specimen was found by Count Taaffe in Ireland, in a jeweller’s box of stones.

It looked like spinel, had a pale mauve tinge, and was cushion-cut, but was eventually found to be a new, doubly refractive (rather than singly refractive like spinel) mineral. Since then, more specimens have been found; these range in hue from red to blue to almost colourless.

Taaffeite occurs in Sri Lanka, China, and the former USSR. No imitation taaffeites appear to exist.

Chemical Composition: 

Oxide of beryllium, magnesium aluminium - BeMg₃Al₈O₁₆ + Fe, Mn, Zn, Cr

Colors / Varieties: 

Purple, violet, red, blue, brownish purple

Crystal System / Forms: 

Hexagonal System / Pyramidal, bi-pyramidal and often truncated by basal pedion (hemimorphic)

Hardness: 

8

Specific Gravity: 

3.62 ± 0.03

Cleavage / Fracture: 

None / Conchoidal fracture

Optic Character: 

Anisotropic, D.R.; Uniaxial negative

Lustre: 

Vitreous

Refractive Index / Birefringence: 

1.718 - 1.722 / 0.004

Pleochroism: 

Weak

Dispersion: 

0.019

Magnification: 

Crystals (spinel etc.), two phase inclusions, liquid fingerprints

U.V. Fluorescence: 

Inert

Spectrum: 

Not characteristic

Cause of Color: 

Pink / Red: Chromium

Simulants (with separation tests): 

Natural spinel (optic character), Idocrase (spectrum, S.G.), Sapphirine (R.I., S.G.), etc.

Geological Occurrence: 

In metamorphosed limestone as rolled pebbles.

Sources: 

Sri Lanka, Russia (Eastern Siberia), China

Cuts & Uses: 

Facetted cuts.