This black color is due to the presence of numerous inclusions, usually graphite, within the stone.
There is some debate about how black diamonds form, but it is believed they may originate from space or through high-pressure conditions on Earth.
The Amsterdam Diamond was discovered in Central Africa, though the specific country is not well-documented.
Africa is a significant source of black diamonds, and many of these gems are found in regions like the Central African Republic or Brazil.
The auction highlighted its rarity, and it fetched a high price due to its size, color, and unique characteristics.