Question

drag the missing word into place lets talk. theyre identified by properties that are physical. color, luster, hardness, streak, cleavage and fracture, now, let me just speak on

Explanation:

The sentence is about something identified by physical properties like color, luster etc. Minerals are substances in geology that are identified by such physical properties. "Formulas" are related to mathematical or chemical expressions (not relevant here as the context is about physical property - based identification). "Inorganic" is an adjective (the blank needs a noun). So "minerals" fits best.

Answer:

minerals