The slabs that follow are from eastern MN and some have the look of binghamite (goethite, quartz, iron). Others are related to stromatolites. I can't guarantee their identity.
3"x2". $1
2.5"x2". Polished on one side. $4
4"x2". $2
4"x3". $3
3"x3.5" $3
3"x1.5" $2
3"x3". $2
3"x1.5". $2
2.5"x2.5" $2
5"x2.5" $3
2"x1.5". $1
2.5"x3". $2
Orange/yellow unidentified. 3"x1.5". $2
Rhyolite. 3"x2" approx. $2
Moss agate with terrific patterns. 3" diam. $5
Cuyunite, 2"x1.5". Polished on one side. $3
Cuyunite, 3"x1.5", polished on on side. $4
Stone with copper inclusions that gleam. 2"x1" and I have two of them. $2
Polished moss agate. 2"x1". $2
Picture stone. 3"x2". Not visible in photo is a mountain that would make a nice 30x22. $2
Yellow, gray and white agate. 2" diameter. $1
Laguna agate. 3"x3". $7
Iron and jasper stripes. 2"x1.5". $4
Saddle Mountain wood. 5"x4". $12
Silky white slab, polished on one side but it didn't take a high polish. 3"x3". $3
Semi-polished fire agate, 1.5"x1.5", with fire in the center that is not visible in the photo. $3
Petrified wood. 3.5"x2". $5
Agate, gray, yellow and white. 4"x3". $3
Green picture stone. 5"x2". $2
Wonderstone. Wyoming. 3"x2.5". $2
Very nice petrified wood. 4"x3". $6
Mary Ellen jasper. 13"x24". $200.
Pyrolite, from NE Minnesota. 15"x12". Polished on one side. $75
Pudding stone. 5"x3". $3
Colorful two-toned pet. wood. $4
Light colored petrified wood. 7"x3". $4
Small good quality binghamite. 3.5"x1". $4
Rainbow obsidian from California. I have multiple cuts of this stone. Thicker slabs more suitable for cabbing and the thinner ones catch the light better. Color is less amber than they photograph and more charcoal, depending on time of day. 4 and 3/4"x4". $5
Rainbow obsidian from California. I have multiple cuts of this stone. Thicker slabs more suitable for cabbing and the thinner ones catch the light better. Color is less amber than they photograph and more charcoal, depending on time of day. 3 and 3/4"x4 and 3/4". $5
Green moss rectangle, polished on one side. 1.25"x2.25". $5
Gem quality tigereye slab. 2.5"x3". $15
Dinosaur bone. 4"x3". $5
Green picture stone. 6"x2". Thick slab. $3
White flame agate with cabochon ovals indicated. $4
Peristerite. Faint blue glow. 7"x2". $4
Unidentified material from Ontario. 3.5"x3". $2.50
Thick granitic material. Very nice. 3"x3". $2
Green triangle, 3"x3". $2
Pretty green slab, 5"x2". $2
This one has shiny strands like asbestos fibers. 4"x3". $1
Yellow plume. Oregon. 6"x2". $3
Black jasper from eastern Minnesota. 5"x6". $5
ND petrified wood. 5"x2". $2.50
Aqua colored spots in what looks like igneous material, origin unknown. 5"x3". $2
Black and white agate with dendrites. 4"x2". $2
Nice red stromatolite formation in thick slab 5"x4". $5
more cabochons and faceted stones