Name	Natural	Non-heat treated points	Heat treated points	Color details	Primary found in:	Associated Formation / Member
Attica Chert AKA: Indiana Greenstone and Independence Chert				Ranges from a greenish gray to gray or blue-gray with occasional mottled or streaked with swirls of light to medium green	East central Illinois	Muldraugh Formation of the Borden Group
Avon Chert				Primarily shades of white with tans and reds occurring	West central Illinois	Burlington Limestone formation
Bailey Chert				Ranges from shades of light gray to tan or beige or caramels	Southern Illinois	Bailey Formation Limestone
Baylis Chert					West central Illinois	Baylis Formation
Blair Chert Blair - St. David Chert				Moderately translucent chert that ranges in color from a medium gray to dark bluish gray with brownish mottling and grayish streaks.	Southwestern Illinois	Carbondale Formation of the St. David Limestone
Blanding Chert Silurian Chert variant				Ranges from white to gray with faint bands of pale yellow, brown, and orange	Northwestern Illinois	Blanding formation
Bowling Green Chert					Southeastern Missouri	Bowling Green Member of the Edgewood Limestone Formation
Burlington Chert				Varies from white to gray or tan.  Banding and mottling may be present	Illinois	Burlington Limestone Formation
Carter Cave Chert AKA for Paoli Chert				Translucent and ranges in color from yellow to tan, red, and orange.  Rarely green and blue are present	Eastern Illinois	Paoli Limestone formation
Cave in Rock Chert					Southeastern Illinois	Ste. Genevieve Limestone formation
Chouteau Chert				Ranges from a light to medium gray.  Oolites form whitish speckles throughout the material with vugs present.	West central Illinois	Chouteau Formation
Clear Creek Chert				Ranges from a slight yellowing gray to white	Illinois	Overlies the Backbone Limestone formation
Cobden- Dongola Chert AKA: Anna Chert, Hornstone, and St. Louis Ball Chert				Shades of dark gray to blue-gray which may be solid or have dark gray bands	Southern Illinois	St. Louis Limestone
Crab Orchard Banded Chert AKA: Gray Banded, Jelly Roll, Kentucky Stromatoporoid chert				Banded gray and white.  It has broad alternating bands of light to dark whites and grays followed by darker grays to almost black	Southeastern Illinois	Crab Orchard member
Crescent Chert (Burlington Chert variant)				Ranges from a brilliant white to a icy blue and commonly banding of darker colors.	West central Illinois	Burlington Limestone Formation
Degonia Chert				Ranges from white to gray and blue	Southeastern Illinois	Degonia formation
Dongola Chert				Dark tan to dark brown with banding of dark brown	Southern Illinois	St. Louis formation
Dover Chert Fort Payne variant AKA: Elco Chert				Range from a light tan to almost a black chocolate brown with swirls, bands, or streaks of light to dark	Eastern Illinois	Fort Payne Formation
Dupo Chert Burlington Chert variation					Illinois
Eagle Point Chert				Ranges from a light gray to a gray.  Fossils form whitish to pinkish speckles.	North central Illinois	Dunleith Formation, Eagle Point Member
Elwood Chert Elwood- Joliet Chert				Ranges from white to gray	Northern Illinois	Elwood formation
Eminence Chert				Commonly gray, but may vary to a dark gray or reddish brown, vugs and fine banding of cloudy white and light gray may be present	Southwestern Illinois	Eminence Formation
Everett  Chert				Gray with vugs present	North central Illinois	Nachusa Formation, Everett Member
Excello Chert				Ranges from a dark bluish black to black.  Chalcedony veins are commonly seen through the material	West central Illinois	Excello Formation
Fern Glenn Chert					Southwestern Illinois	Fern Glenn formation
Fort Payne Chert				Ranges in color from black to a grayish blue, or white to a bluish white.  Bluish gray is the predominate color with bluish hues	Southeastern Illinois	Fort Payne formation
Galena Chert Platteville-Galena Chert				Ranges from gray to light tones of brown ,mottles and swirls White specks of fossil fragments.  Small flat vugs may be present.	Northern Illinois	Platteville Dolomite formation
Gower Chert					Northwestern Illinois	Gowen Formation, Silurian System
Grassy Knob Chert				Ranges in color from a pale yellowish gray to a light olive brown	Southeastern Illinois	Bailey Limestone formation
Grime Hills Chert Burlington Chert variant					Southern Illinois	Burlington Limestone Formation
Grover Gravel Chert Lafayette Gravel variation				Ranges from brown to tan, greyish tan, yellowish tan, or cream. Mottling is commonly seen, and rarely banding may be present.	West central Illinois	Lafayette Gravel Formation
Harmilda Chert AKA: Bolingbrook Chert, Sugar Chert, Crystal Chert				Semi-transparent and region.  The Semi-translucent portion ranges from tan to gray and the opaque regions range from white to gray.	Northeastern Illinois	Silurian System
Harvester Creek Chert				Mottled light tannish brown to an orangish brown	West central Illinois	Salem Formation
Hopkinton Chert				Translucent light gray with white opaque mottling	Northwestern Illinois	Hopkinton Formation
Joliet Chert Elwood- Joliet Chert				Ranges from white to gray	Northern Illinois	Joliet formation
Kankakee Chert AKA for Blanding Chert Silurian Chert variant				Ranges from white to gray with faint bands of pale yellow, brown, and orange	Northwestern Illinois	Blanding formation
Kaolin Chert				Ranges from hues of golden tans to gray and reds.  Light banding may be present.	Southern Illinois	Paleozoic Limestone formation
Keokuku Burlington variant				Ranges from creamy white to grays with yellow and brown streaking	West central Illinois	Keokuk Member
Kincaid Fossiliferous Chert				Ranges from a light gray or bluish gray to brown in color with speckles formed by fossils.	Southern Illinois	Kincaid formation
Kornthal Chert Breccia AKA: McNairy Chert Breccia				Brecciated to conglomeritic ranging from a pinkish gray, to red most common, blue, yellow, brown, and inclusions of white chert or quartz	Southwestern Illinois	McNairy Formation
Lafayette Chert				Most commonly ranges from brown to tan, greyish tan, yellowish tan, or cream, less common white and black occur. Mottling or rarely banded	Southern Illinois	Lafayette Gravel Formation
Lafayette Quartzite					Southern Illinois	Lafayette Gravel Formation
Lower Nachusa Chert				Ranges from a slightly mottled white and gray	North central Illinois	Nachusa Formation
Mansker Chert				Ranges in color from a tan to a dark brown or gray.  Speckles from fossil remains may be present.	Southwestern Illiois
Maquoketa Chert AKA: Silurian 2 Chert				Ranges in color from a pale olive gray to a pale gray.  Banding or streaking may be present.	Northwestern Illinois	Maquoketa Formation
McNairy Quartzite				Tightly packed pale yellowish quartzite with limited or no inclusions.  Red staining may be present.	Southwestern Illinois	McNairy Formation
Mill Creek Chert				Vary from white to gray, grayish brown, orange white to orange gray, or pale blue to black.  Concentric banding may be present	Southern Illinois	Salem / Ullim Limestone formation
Montrose Chert				Light to medium bluish gray and often resembles a chert breccia.	West central Illinois	Montrose Member of the Keokuku Limestone Formation
Mounds Gravel Chert AKA: Elco Gravel Chert Lafayette Chert variation				Most commonly ranges from brown to tan, greyish tan, yellowish tan, or cream.  Less commonly white, black, pink, red, olive gray or greenish gray	Southern Illinois	Lafayette Gravel Formation
Oneota Chert AKA: Oneota Prairie de Chein Chert (lower)				Ranges from white to gray or yellowish or orange	Northern Illinois	Lower Prairie de Chien Group,  Oneota formation
Osage Chert Osage Undifferentiated Chert				Ranges from a white to light gray or light brown.  Occasionally gray to dark gray mottling is present.	Southwestern Illinois	Osage Series
Paoli Chert AKA: Carter Cave Chert				Translucent and ranges in color from yellow to tan, red, and orange.  Rarely green and blue are present	Southeastern Illinois	Paoli Limestone formation
Payson Chert AKA: Adams County Flint				Banded ranging in color from a tan to orange or red	West central Illinois
Platteville - Galena Chert Galena Chert				Ranges from gray to light tones of brown ,mottles and swirls White specks of fossil fragments.  Small flat vugs may be present.	Northern Illinois	Platteville Dolomite formation
Prairie du Chein Chert				Mottled and ranges in color from an off white to a light cream	Northwestern Illinois	Prairie du Chein group
Racine Chert AKA: Engadine Chert				Ranges from a grayish white to a medium gray or bluish gray.  Mottling or streaks of bluish tints may be present	Wisconsin, Illinois	Racine Limestone Formation
Salem Chert				Ranges from a dull brown to gray	Southern Illinois	Salem Formation
Sexton's Creek Chert				Ranges from a light bluish gray to a caramel brown	Southwestern Illinois	Sexton's Creek Limestone Formation
Shakopee Chert				Ranges from white to gray with contrasting banding	Central to northern Illinois	Shakopee Dolomite formation
Spergen Chert AKA: Spergen Crystalline Saccaroidal Dolomite				Commonly banded or mottled and ranges in color from a very light gray to a gray or brownish gray, and a pale yellow to a tan	West central Illinois	Spergen Formation
Sonora Flint AKA for Wyandotte Chert				Vibrant colorful flint that may range from tans to light gray-blue and dark brown to purples	Southeastern Illinois	Ste. Genevieve Limestone formation
Spoon Chert				Opaque and ranges from white to light gray with darker banding present	West central Illinois	Spoon Formation, Kewanee Group
St. David Chert Blair - St. David Chert				Moderately translucent chert that ranges in color from a medium gray to dark bluish gray with brownish mottling and grayish streaks.	Southwestern Illinois	Carbondale Formation of the St. David Limestone
St. Louis Green Chert AKA: St. Louis Formation Chert				Varying shades from light gray green to yellow green	Central to southern Illinois	St. Louis Formation
Starved Rock Chert AKA: LaSalle Chert Oneota Chert variation				Ranges from white to a light olive gray or gray and from a light brown to a light yellow with darker colored banding.	North central Illinois	Lower Prairie de Chien Group,  Oneota Formation
Ste. Genevieve Chert AKA: Old Blue Chert				Ranges from light to medium blue, gray, and black, to olive gray and yellowish gray with gray concentric bands commonly present	Southern Illinois	Ste. Genevieve Limestone Formation
Strawberry Chert					Western Illinois
Ullin Chert				Brownish gray color	Southern Illinois	Ullin Formation
Utica Jewelstone				White with banding of gray and brown.	East central Illinois
Vienna Chert				Ranges from a deep bluish black to a light grayish tan or pinkish	Southeastern Illinois	Vienna Formation
West Franklin Chert				Ranges from a light gray to light bluish gray.  Commonly mottled with blue and with light brown streaks and chalky vugs	Southeastern Illinois
Wyandotte Chert AKA: Indiana Hornstone, Harrison County Chert				Ranges in color from a medium bluefish gray to a medium light gray.  Banding is common and is various shades of gray	Southern Illinois	Fredonia Member of the Ste. Genevieve Limestone formation
Yankee Town Chert				Ranges in color from a light gray to a pale yellow.  Banding may be present, has a "knotty" appearance.	Southwestern Illinois	Yankeetown Chert Member of the Cedar Bluff Group