Middle Eocene period Tallahatta silicified sandstone from southeast MS & south AL was used for making projectile points as early as 9000 years ago. #archaeology#rocks
Found a puzzling object while out on a walk. At first I thought it was a piece of driftwood but it’s very heavy rock. We get fossilised wood in this area but we also get slag from old smeltworks, so I’m used to finding both. I did wonder if it’s a knotty bit of fossilised wood but maybe it’s a weird bit of slag? The pattern on the lumpy bits is absolutely beautiful #fossil#rocks#geology#slag
#nature#rocks
Very special color today because of the light - they seem blueish and are actually grayish, with a yellow touch - we're lucky living near rocks that really have many different color shades 🥰
Ferric oxide in a fracture plane of Big Fork chert from the central Ouachita Mountains of Arkansas.
Perfect example of how ferric oxide turns red with heat. In this case it started as a rusty brown ferric oxide stain. The chert itself didn't change color or luster from the heat.
This red change due to heat is why potters used red ochre/hematite mixed with clay to form red slips & paints. #archaeology#ceramics#rocks
11 different novaculites & the Big Fork chert to heat treat: dark blue-gray; medium gray w/ black dendrites; light brown w/ black dendrites; off-white; black; tan w/ black streaks; beige; tan; white; & pinkish-white. I'll use this photo to ID the novaculite types after they are heat-treated. #archaeology#rocks
Where to begin? I need at least 4 samples of each novaculite & Big Fork chert: 2 raw & 2 for heat treating. That will give a comparison of each color before & after thermal alteration. #Archaeology#rocks
Got the microscope camera today. I can't do anything about the yellowing on the old microscope's internal lens, but at least all of my lithic material photos will have the same lighting. Here is a black novaculite sample at 31.5x. The whole image represents 3.92 mm. #archaeology#rocks
Relevancy. In looking at my various samples of black novaculite in comparison to some artifacts suspected to be the same material, I needed to be sure they weren't Big Fork chert. Now I know they aren't. 3/ #archaeology#rocks
Microscopic inspection confirms reddish-brown carbonate rhombs noted in Banks (1990), with some areas of the rock exhibiting what appear to be occasional fossil sponge spicules & asphaltum vugs also noted by Banks for Big Fork chert. 2/#Archaeology#rocks
Really funny. I wasn't sure what Big Fork chert from the Ouachita Mountains looked like until watching a flintknapper identifying specimens. I realized that the quartz-striped, black rock I had from the region was Big Fork chert. 1/ #Archaeology#rocks