In any case, anyone with a shovel and a piece of ground that is reasonably untouched — that is, that has not been plowed up recently — can become an amateur soil scientist. Soil scientists study soil horizons, or layers of soil that lie parallel to the surface of Earth and which have built up over time. These layers are distinguished from one another by color, consistency, and composition. A cross-section combining all or most of the horizons that lie between the surface and bedrock is called a soil profile. The most basic division of layers is between the A, B, and C horizons, which differ in depth, physical and chemical characteristics, and age.
A fake is any gem material, natural or synthetic, which is misrepresented to be any other gem material, natural or synthetic. A synthetic ruby, a natural red spinel, or a piece of red glass would all be fakes if represented as natural rubies. Whether something is a "fake" rather than a synthetic or a simulant is a matter of intention and disclosure. When misrepresentation occurs (whether knowingly or not) then you have a fake. Fakes have been around as long as there have been been dishonest, and greedy sellers and gullible buyers.