Rock Types

noun a hard gray rock consisting of nearly pure chert, used for making sparks or tools

• Archaeologists discovered flint tools dating back to the Stone Age.
• I found a piece of flint in the backyard while gardening.
• Let's start a fire with some flint and steel.
• His wit was as sharp as flint, cutting through any argument with ease.

noun a rare type of granitic rock containing a high percentage of orthoclase feldspar

adjective relating to or characteristic of adamellite rock

• The geologist identified the rock as adamellite due to its composition of quartz, feldspar, and biotite.
• I found a cool adamellite rock while hiking in the mountains.
• Check out this shiny adamellite I picked up by the river!
• Her personality was as solid and enduring as adamellite, never wavering in the face of challenges.