Yes, slithers of which, when broken from a bigger lump (known as 'knapping') have sharp cutting edges.
It certainly is not rock salt. It is a shame that WA strips out punctuation. Try searching your reading or notes for the word "Flint".
Flint is a microcrystalline sedimentary rock composed primarily of quartz, exhibiting a conchoidal fracture which made it useful in tool making.
Granite.
Flint is a chemical sedimentary rock formed from the precipitation of silica rich solutions in layers of marine sediments.
Granite is a very hard rock.
Flint is a hard rock that produces a spark when struck against steel. Flint is a sedimentary rock that is formed from a crypto crystalline quartz.
A hard gray rock consiting of nearly pure silica.
Flint is a very hard rock and forms very sharp glassy flakes when hit with another flint. Flint was used to make knife blades by early man and is the ancient remains of sea sponges and are found in layers in chalk. Flint was also used to generate a spark in tinder boxes(a predecessor to matches) and to ignite gunpowder in early firearms.
Flint is the State stone/rock of Ohio.
Flint
When you rub steel against a very hard, sharp rock such as flint, it cuts very tiny flakes of the steel off and a high amount of heat is created by the great friction. When the tiny flakes of steel are heated, they combust thus showing the spark.
Flint is a rock that you rub to make fire.
Flint stone is used for making sparks to start a fire
Slayer are a thrash metal band that rock very, very, very hard. So if you rock like Slayer, you rock very, very, very hard.
flint has an extremely bright shine
The anagram is flint, a hard rock or similar sparking implements used in lighters.
Lime stone varies from crumbly to almost as hard as flint, depending mostly on how much weight was above it when it was being formed.