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elbaite
member of the tourmaline group, forms series with liddicoatite, schorl and dravite; first found 1913 on the italian isle of elba, hence the name. elbaites occur in many colours. most famous and sought-after are the blue, purplish-blue and green copper-bearing elbaites from paraïba, brazil.
the discovery of copper-bearing tourmalines in nigeria and mocambique sparked a heated debate whether these new stones may also be termed paraïba tourmalines.
we of the Vienna Gem Center hold the opinion that only elbaites from paraïba, brazil, should be marketed as paraïba tourmalines. in accordance with leading international authorithies we call copper-bearing elbaites from other localities or stones with uncertain origin "paraïba-type tourmalines".

emerald cut
octagonal step cut, the classic cut for emeralds to avoid any damageable sharp edges

epiasterism
when the star is best visible in reflected light, example: star sapphire
also see asterism
opposite of diasterism

euhedral
well-formed, external crystal faces well developed, opposite of anhedral

eyeclean
when a trained expert cannot see any inclusions with the unaided eye

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