Is it Green Beryl or Emerald?
Trace Elements and Colour
The colour of beryl is determined by the trace elements present at formation of the gems. Aquamarine is coloured by the trace element Iron. Some greenish blue aquamarine is heated to bring out more of the blue colour, but this is not always possible. Beryl that leans to this gorgeous sage green colour is a beautiful gem in its own right and is simply called green beryl.
Green Beryl or Emerald?
So why is it called green beryl rather than emerald? They are structurally the same mineral species (beryl), with very similar characteristics in terms of hardness, durability and lustre. However their colour is very different: green beryl is an attractive greyish green gem, whereas emeralds come in much stronger greens, often with a blueish hue.
The colours in each gem are caused by different trace elements. Where green beryl - like aquamarine - is caused by the presence of the trace element iron, the deep green emerald includes trace elements of chromium or vanadium (and sometimes both). Emerald may also have traces of iron leading to a yellower green colour. Some crystals may have chromium and/or vanadium at one end, but none at the other end - technically one end is emerald, whilst the other is classified as green beryl.
As iron is one of the most abundant elements on earth, it makes sense that green beryl is much more prevalent than emerald - which requires the rare trace elements of chromium and vanadium. In fact emerald is 20 times rarer than diamond! Understandably emerald's rarity leads to higher prices per carat.
Prices for vary widely from $5 per carat for low quality gems, to over $10,o00 for large top quality faceted emeralds. In contrast green beryl is available at much humbler prices with rough stones fetching around $2 dollars per carat.
Emeralds tend to have quite a few inclusions - called "jardin" - which can sometimes affect its resistance to scratching or breakage. Emerald tends to be treated with oil to reduce the appearance of inclusions and improve clarity. However the treated gems need minding to avoid leaching the oil out, reversing the treatment. That said a good quality emerald ring will last the wearer a lifetime and emerald necklaces earrings or brooches are often heirloom pieces.
Green beryl, like aquamarine, is typically much less included though there are also some lovely translucent green beryl gems with silky inclusions. Green beryl tends not to be treated at all and as such the more stable and durable gem.
Beryl at DesignYard
Curious to find out more about Beryl? At DesignYard you will find jewellery with the different beryl varieties - from pink morganite, aquamarine, green beryl, emerald and even some golden beryl. Book you appointment to explore the different varieties in person.