different meanings for clay

did anyone take notes for the last PPT regarding different terms for clay (bonus question asked before class ends)? i thought it would be posted on the PPT, so i did not take notes.

in the lab manual, textbook, and lecture notes there is a table that shows you different textural classifications of soil based on percent clay vs percent sand. is this what you mean?

That gives you 1 meaning, but there are more

It seems that the meaning of the word varies depending on what aspect of soil we're focusing on, like composition, structure or origin, etc.

Clay is a: a) textural class (e.g., clay, heavy clay, silty clay, etc. as identified on textural triangle) b) particle size (other particle sizes are sand and silt) c) a type of soil colloid (particle with diameter < 2 micrometer) that occurs in various forms/structures, such as phillosilicates. **other materials in the soil that act "colloidal" (ie. reactive, high specific surface area, high H2O absorption) are Fe and Al oxides; amorphous minerals (no obvious crystalline structure), and organic compounds (humus)** d) secondary silicate clay mineral (e.g., pillosilicate minerals) derived from a primary minerals (quartz, feldspar, mica) after thousands of years of weathering

Possible confusion might come if just word "clay" is mentioned in text since it means both "mineral particle size" and "textural class" (edited by Maja Krzic)