sgatlant - - is right. You have a couple of other good answers much along the same lines.
The chemical phenomenon of small molecules being adsorbed by the surfaces of solids is well understood. Note -aDsorbed, not aBsorbed. This is may be a single layer of the small molecules on the surface but it can also be thicker. The amount adsorbed will change with physical conditions.
Because the surfaces of solids have a slight electrical charge, and chemical reactions are about the exchange or sharing of electrons between atoms, adsorption can assist with making chemical reaction go ahead. Some reactions are nearly impossible to do without such assistance but with the right solids they will happen quite rapidly. This is called catalysis.
Added to the bulk effects are rather more refined ones. Solids are often crystalline, that is the atoms in them are arranged in a particular way. All true minerals are crystalline. All molecules have a particular shape, even simple things like water. So a small molecule with a particular shape can arrange itself on a crystalline surface in a particular way. Another molecule, either of the same compound or a different but similar one could lie on the surface in the same way.
Very good examples of molecules of different compounds but with a similar overall layout are the amino acids. These have a general structure when neutral of NH2-CH(R)-COOH. The -COOH is the acid part, and is the active thing in vinegar, while NH2- is the amino part and is derived from ammonia.
The R means any one of dozens chemical groups that may themselves be acid, basic or neutral. In nature the COOH group of one molecule can react with the NH2 part of another and the result can form long chains called peptides or proteins. These peptides and proteins can themselves be chemically active because of their own shape and distribution of electrical charge.
This effect can also work with molecules like DNA and RNA which are also long chains. RNA is particularly fond of calcium phosphate, a relatively common mineral in nature.
EDIT- that probably should read "some clay minerals" rather than "calcium phosphate". I can't quite remember which.
Creationist leaders get away with ridiculing these facts because their audiences know nothing or next to nothing of physical chemistry, catalysis or stereochemistry, which is about the shape of molecules. They can say that "evolutionists say that life came from rocks" but that is false. What is being suggested is that life may have been facilitated on crystals.
The people who wrote the early parts of the Bible may not have known a lot but they were not stupid. They also inherited maybe a thousand years of some rough and ready "science" from the Mesopotamians and Egyptians. It might have been pretty clear that dead things turned to "dust" particularly in an arid climate, so it's not unreasonable to think they might have been formed from it in the first place.