EXAMPLE OF NON-DIRECTED QUESTIONING:
(1) Is this rock sample shale?
EXAMPLE OF LEADING QUESTIONING :
(1) Shale is a sedimentary rock.
- What features might indicate that this is a sedimentary rock, and not a metamorphic or igneous rock?
(2) Shale is formed by the compression of clay or mud.
- Does this look like compressed mud?
(3) Since shale is made of mud, it is scratched by metal such as coins, but not by fingernails.
- Will metal scratch this?
- Will fingernails scratch it? (Moh's hardness scale: 2: scratch with fingernail, 3: scratch with a copper penny)
(4) Shale often smells like mud when wet.
Does this smell like mud or clay when wet?
(5) On the basis of your observations, do you think it is shale?