Cat’s Eye :- Cat’s Eye describes a gemstone polished into cabochon that displays a narrow band of concentrated light going across the width of stone. This effect, known as chatoyancy or cat’s eye effect is caused by inclusions of fine, slender parallel mineral fibres in the gemstone that reflect light in a single band.

Alexandrite :- Alexandrite with its chameleon –like mineral chrysoberyl . Its color can be lovely green in daylight or fluorescent light changing to brownish or purplish red in the incandescent light from a lamp or candle flame. This is a result of complex way the mineral absorbs light. According to popular but controversial story. Alexandrite was discovered by the Finnish mineralogist Nils Gustaf Nordenskiold (1792-1866) and named alexandrite in honour  of the future Tsar Alexander II, of Russia.