The dark veins are matrix, or host rock, which can be part of the beauty of turquoise.
Veins
The light-colored veins in this rough turquoise are called matrix, part of its host rock.
Robin's Egg Blue
Turquoise with an even, pure sky blue color is very valuable. People call the color robin’s egg blue.
Turquoise is a colored stone found only in places that are dry and barren. People like its color and its rich history. The colors of this stone range from different shades of green to a bright sky blue called “robin’s-egg” blue. In the U.S., it is famous for its jewelry made by Native Americans. It also has a rich history with the ancient Egyptians and Chinese people.
Colors
Turquoise gets its beauty from its blue to greenish blue to green colors.
History
1519
Montezuma
The Aztec emperor Montezuma thought the Spanish conquistador Cortes to be a god named Quetzalcoatl. He gave Cortes offerings of that god’s favorite gem, which was turquoise.
Famous Turquoise
King Tut’s golden funeral mask was adorned with gemstones, including turquoise. - Jon Bodsworth
what's in a name?
Turquoise
[tur-kwoyz]
(noun)
The word “turquoise” comes from a French word that means “Turkish stone,” because it is possible that turquoise first came to Europe from Turkey.