What percentage of dietary iron is absorbed from mixed (i. e., those that also contain meat) diets?

Mixed diet is consuming different types of food, animal based food, meat , but also plant based food (vegetables and fruits). Iron differs from other minerals because iron balance in the human body is regulated by absorption only because there is no physiologic mechanism for excretion. Different type of diet has different iron absorption.
18% of dietary iron is absorbed from mixed diet.

C. gemstones they are the only non metallic mineral from the list.