10 Most Expensive Materials in the World - Bullion For Less 10 Most Expensive Materials in the World | Page 9

Diamond
($2,500 to
$16,000 per
carat)
Diamonds have a high
refractive index due to which
they seem to shine with a
light of their own. Solitaires
and finely cut diamonds are
one of the most sought-after
gemstones in the world.