Iliac crest pain is not that common in the general population, but it is frequent in older individuals, runners (and athletes in general), lower back pain sufferersâ¦ But that doesn`t mean âregularâ people like you and me can`t experience it from time to time!
The mantle is composed of iron-magnesium silicates, and the crust is composed of roughly 5 percent iron. All together, iron makes up an estimated 35 percent of the Earth's mass. Oxygen. Oxygen, the second most abundant element on Earth, is found mainly in the crust.
Oxygen is the most common element on earth. This is followed by  silicon, aluminum, iron, magnesium, calcium, sodium, and potassium.  These elements make up 99 oercent of thâ¦e earth's mass. All other  elements combined make up less than 1 percent of the remaining  mass.