WHAT IS A GEM? 021
How qualities add up
Value, quality, and different varieties
Gems are defined by the very qualities that give them their value (see
pp.30–31) – a gem would not be a gem without some level of material
purity and craftsmanship. However, not all gems are equal.
COMPARATIVE GEM VALUES
The chart below compares a selection of popular gemstones according
to their approximate monetary value (see p.27 for information on valuing
diamonds, not included here). Varieties such as alexandrite, sapphire, and
ruby are scarce and sought-after, and thus expensive; others, such as ruby,
can vary hugely in cost, from modest to priceless. In general, the greater
the clarity, size, and beauty of colour, the more you will pay.
Tanzanite
Topaz – pink
Topaz – imperial
Tourmaline – green
Spinel – blue
Spinel – red
Sapphire – pink
Benitoite
Sapphire – padparadscha
Tourmaline – blue
Cat’s eye
Garnet – demantoid
Opal – black
Ruby – star
Sapphire – blue
Alexandrite
Emerald
Tourmaline – paraiba
Ruby
Gemstone Modest Affordable Expensive Very expensive Priceless
020-021_INTRO_What_is_a_gem.indd 21 18/05/2016 14:42