This pair of Fossil Mastodon Ivory Post Earrings is estimated to be well over 300,000 years in age. The color is from minerals that are absorbed from the soil in Alaska were the Ivory was unearthed.
As with most fossil ivory the color pattern can be different even though the 2 pieces were cut from the exact same piece of ivory, side by side. Truly hand painted by nature, one of a kind. The photo does this set no justice.