Chert

Chert is a sedimentary rock that's made up of a cryptocrystalline structure composed of microcrystalline quartz and other trace elements. It's also known as flint, and is commonly found in seabeds, lakes, hot springs, and on the Earth's surface.

Colors It Comes In - White, Grey, Black, is most commonly found in shades of Gray, Brown, Grayish Brown, Light Green, and Rusty Red. The color is determined by trace elements present in the rock, with Red and Green often indicating different oxidation states of Iron.

Fracture - Conchoidal

Luster - Waxy or Resinous

Shape - Nodules, Concretions, Bedded

Texture - Smooth, Waxy Feel

Streak - White

Locality - Chert is very abundant and can be found almost everywhere. In some areas, like the Ozarks of Missouri, you can find chert lying all over the ground. That is because flint and chert are hard, durable rocks that are so resistant to weathering they remain intact long after the surrounding rocks have weathered away into the soil.

Where They Can Be Found - Chert is found in settings as diverse as hot spring deposits (siliceous sinter), banded iron formation (jaspilite), or alkaline lakes.

Hardness On The Mohs Scale - 7 Out Of 10