What Is The Difference Between Chert, Flint, And Mozarkite?
by International Gem Society
“Chert (Flint) 1” by James St. John is licensed under CC By 2.0
Question
I’m a little confused about chert and flint. In your gemstone listing entry on quartz, you identify both chert and flint as examples of cryptocrystalline quartz. They are described together as “opaque, dull gray, or whitish chalcedony, very compact and hard.” Are chert and flint the same mineral?
Thanks,
John
"Flint Is A Variety of Chert
Although there is a lot of confusion on this, chert refers to cryptocrystalline or polycrystalline quartz that usually forms as nodules in limestone. Flint is reserved for such material that forms in chalk or marl. Flint is simply a type of chert. (At least this was the distinction that was made in the literature when I was a geology student 35+ years ago).
Paul
Mozarkite: The Show Me Chert
There’s more to the story regarding chert and flint. Although chert and flint are described as “opaque, dull gray, or white” and said to rarely appear as jewelry, this is not always the case.
I am a member of the St. Louis Mineral and Gem Society. Our club ... "
https://www.gemsociety.org/article/what ... amond_cost