The term is "minerals." Few elements are found in their pure elemental form, and they are mostly metals.
When the masses of naturally occurring isotopes of an element are averaged, the result is called the element's average atomic mass.
Minerals are the compounds found in rocks. They are naturally occurring substances with a specific chemical composition and usually have a crystalline structure. Minerals make up the building blocks of rocks.
The Earth is a naturally occurring magnet (it has a north and south pole. The mineral magnetite is also magnetic.
Lead is an element---Go to http://en.wikipedia.org/ and look up lead---Natural or Synthetic is irrelevant when you're talking about elements. (If you don't know what I'm talking about, then maybe you ought to also read the wikipedia article on Chemical Element.)
The weighted average of all of the natural occuring isotopes for a particular element is called its Atomic Weight (or Relative Atomic Mass)
Synthetic
Almost all inorganic compounds contain metals, depending upon the type of bonding. These are mainly of 2 types: salts and complexes. Mostly alkali and alkaline earth metals form salts while transition metals form complexes.
Elements found in nature are referred to natural elements, as opposed to synthetic, which are man made.
3 quarters of the 90 naturally occurring elements are called metals.
Elements and compounds found in the lithosphere are referred to as minerals. Minerals are naturally occurring inorganic substances with a specific chemical composition and crystal structure. They form the building blocks of rocks and are essential for various Earth processes.
Atomic weight, if the average is taken by weighting the mass of each naturally occurring isotope by its natural abundance.
Naturally occurring elements are created through nuclear fusion in the cores of stars through a process called nucleosynthesis. These elements are then dispersed into the universe through supernova explosions and stellar winds, eventually forming into planets.
When the masses of naturally occurring isotopes of an element are averaged, the result is called the element's average atomic mass.
Elements are composed of only one type of atom. There are about 90 or so naturally occurring elements.
... atomic mass or atomic weight.
This is the atomic weight of the element.
Air contains naturally occurring chemicals called hydroxyl radicals that react with, and destroy, a range of pollutants and natural compounds