BACK TO FLINT TYPES
Harvester comes from the Salem formation and is usually found in rounded balls or rounded ball sections. It frequently has concentric rings in the nodule. Sometimes, the central area, of the nodule, has reddish or pinkish color. It grades from poor to very high quality and takes heat-treating well.
Above, is some of the plainer, raw harvester. Plain but high quality Harvester, that is.
Above, is one of the more unusual pieces of raw Harvester showing that Harvester has some cool variations.
This is probably the most unusual heated Harvester around. Both these pieces may have come from the same nodule. Harvester is generally a ball chert but the balls break up in the creek, usually presenting the finder with ball sections rather than full, rounded, nodules.
And then there's the "Smiley Face Harvester"
Here's its close-up.
Here's some Salem chert from the area of Valmeyer Il. It's still in it's original matrix.
For more information, check out the Parkland College CHERT TYPES pages.