Materials Identification Guide

North Dakota Lithic Material

 










Name Natural Non-heat treated points Heat treated points Color details Primary found in: Associated          Formation / Member
Antelope Chert
Silicified Peat		 Ranges in color from a purple to tans.  White gastropod shells are found throughout the material. West central North Dakota  
Basalt   Ranges from black to gray Western North Dakota Volcanic
Bear Den Kaolin     Western North Dakota Bear Den Member of the Golden Valley Formation
Chalky Butte Chert   Western North Dakota Chalky Butte Member of the Chadron Formation
Charlie Creek Chert Ranges from red to gray and white with black dendritic inclusions are present. Western North Dakota  
Flaxville Quartzite Gravel   Light gray color Northwestern North Dakota Flaxville Formation
Fort Union Porcellanite
AKA: Powder River Chert		   Ranges from most commonly a light gray to a light purple or red. Southwestern North Dakota Fort Union Formation
HS Silcrete
AKA: Hard Siliceous Silcrete		   Ranges from a dark brown to black with mottled patches of gray. Southwestern North Dakota Camels Butte Member of the Golden Valley Formation
Knife River Flint
Knife River Chert, Knife River Chalcedony		   Ranges in color from a root beer, tea, coffee, or caramel brown North Dakota Eocene Golden Valley Formation
Lake of the Woods Chert Ranges from a white mottled with green to a homogenous dark green to black color Northeastern North Dakota South Kakagi Lake Formation
Lake of the Woods Rhyolite
   Ranges in color from a greenish gray to less commonly a gray.  Streaks of brown to orangish brown may be present. Northeastern North Dakota  
Little Heart Chalcedony   Mottled white. North Dakota  
Obsidian
AKA: Volcanic Glass		   Black to black with bands of dark reds (mahogany obsidian) or white flakes (snowflake obsidian) Western North Dakota Volcanic
Petrified Wood
AKA: Agatized Wood, Opalized Wood		   Vary in color based on the minerals present during the process North Dakota Varies
Porcellanite
Generic type		   Ranges from white to brown or various shades of gray Western North Dakota Varies
Rainy Butte Chert
AKA: Rainy Butte Silicified Wood		 Ranges from a dark reddish brown to a dark chocolate brown with yellowish streaking containing fossilized wood Southwestern North Dakota Sentinel Butte formation
Red River Chert Ranges from white to light gray or light brown and may vary from a solid color to mottled Eastern North Dakota  
Rhyolite   Gray to grayish black, flow banding may be present alternating from light to darker gray North America Volcanic Activity
Sentinel Butte Porcellanite   Light green color Southwestern North Dakota Sentinel Butte Shale Member of the Fort Union Formation
Swan River Chert Ranges from a creamy white to gray, pink to a rust, or pale yellow to deep orange, commonly has banding Central to eastern North Dakota Souris River Formation, Point Wilks Member
Taylor Bed Silcrete
AKA: Taylor Bed Chert / Taylor Bed Quartzite		 Ranges from a gray to light tan commonly iron stained.  Remnants of wood and cattails are commonly present Southern North Dakota Dean Member of the Golden Valley formation
Teredo Petrified Wood   Primarily black or dark gray with prehistoric Teredo (worm shaped mollusk) boring or worming through the wood. Central North Dakota Cannonball Formation
Tongue River Silicified Sediment
AKA: Tongue River Silica		   Grayish brown sediment, pseudoquartzite, or arenaceous chert Southern North Dakota Slope / Bullion Creek formation
Tuff
AKA: Solidified Volcanic Ash		   Contains greater than 75 volcanic ash and ranges from white to tan, gray or pink. North America Volcanic activity
White River Group Silicate
Generic type		   Ranges from light to medium gray, to a light brown, pink, blue or lavender with inclusions, splotches,mottling.  Western North Dakota. White River Group