Turquoise Blue, Lapis Blue. These two gemstones are the only two rock gemstones. Most gemstones are crystalline ( Garnet, Diamond, Amethyst, Emerald etc etc ) and some are organic, e.g. Pearl, Amber, Coral.
And both these rock gemstones are blue, Turquoise Blue being synonymous with the blue of the sky since before the written word, the deep blue of Lapis Lazuli being so distinctive that it has been given its own name: ultramarine.
In Ancient Egypt craftsmen often paired the two blues of these two gemstones in inlaid work. The prime source of Turquoise for Egypt in ancient times was Sinai,  totally within the Empire, but all the Lapis Lazuli needed to be caravaned in from the far north-east of Afghanistan, across Iran and down into Mesopotamia and beyond, a long arduous journey which would no doubt have involved the gemstone rough changing hands many times.