Turquoise or turquoise blue is used to describe things that are of a light greenish-blue colour.
...a clear turquoise sea.
2. variable noun [oft NOUN noun]
Turquoise is a bright blue stone that is often used in jewellery.
...beautiful silver and turquoise jewelry and pottery.
turquoise in British English
(ˈtɜːkwɔɪz, -kwɑːz)
noun
1.
a greenish-blue fine-grained secondary mineral consisting of hydrated copper aluminium phosphate. It occurs in igneous rocks rich in aluminium and is used as a gemstone. Formula: CuAl6(PO4)4(OH)8.4H2O
2.
a.
the colour of turquoise
b.
(as adjective)
a turquoise dress
Word origin
C14: from Old French turqueise Turkish (stone)
turquoise in American English
(ˈtɜrˌkɔɪz; ˈtɜrˌkwɔɪz)
noun
1.
a greenish-blue, hard mineral, hydrous copper aluminum phosphate, CuAl6(PO4)4(OH)8·5H2O, used as a gem
2.
the color of turquoise; greenish blue
adjective
3.
greenish-blue
Also sp. ˈturquois
Word origin
ME turkeis < MFr turqueise, fem. of OFr turqueis, Turkish (see Turk1): orig. brought to western Europe through Turkey