Lapis Lazuli
The only major source of Lapis lazuli is in northeastern Afghanistan, yet the Ancient Egyptians were using it before their country was unified under a centralized government. Upper Egypt's Naqada Predynastic site has yielded the earliest Egyptian Lapis jewelry found so far, which is dated 3300–3100 BCE.
Powdered Lapis was used to make the original Ultramarine pigment, until a synthetic was developed during the early 19th Century.
Lapis is mostly composed of the mineral Lazurite, usually with Calcite (white) and Pyrite (gold).
The above image (and a color picker) produced this blog's original background color, and it became the background image once we could use them.