Name	Natural	Non-heat treated points	Heat treated points	Color details	Primary found in:	Associated              Formation / Member
Absaroka Chert				Primarily green in color	Southwestern Montana
Agate Jasper				Ranges from yellow to brown or green.  Part if the material will be banded and be translucent while the remaining material will be mottled and opaque.	Montana
Ahorn Quartzite				Primarily pink to maroon or a dark green to a greenish gray.	Western Montana	Hoadley Formation of the Belt Series
Antelope Chert Silicified Peat				Ranges in color from a purple to tans.  White gastropod shells are found throughout the material.	Northeastern Montana
Appekunney Argillite				Ranges from black to a gray or greenish gray with inclusions of white quartzite.	Northwestern Montana	Appekunney Member of the Belt Series
Avon Chert AKA: Avon Valley Porcellanite				Porcelain white with brown chalcedony inclusions	Northwestern Montana
Ayers Quartzite					Western Montana
Basalt				Ranges from black to gray	Montana	Volcanic
Bear Canyon Agate				Banded ranging from black and white to a dark gray and white.	South central Montana
Belt Argillite				Ranges from a medium gray to a greenish gray with casts commonly present.	West central Montana	Belt Supergroup
Big Horn Chert / Jasper				Ranges from red to purple with patches of tan	Southern Montana	Big Horn Formation
Bonner Quartzite				Ranges from most commonly pinkish gray to pale red.  Less commonly reddish gray to red or greenish gray.	Western Montana	Bonner Quartzite member of the McNamara Formation, Missoula Group
Bowman Chert AKA: Bowman Porcellanite				Porcelain white with brown chalcedony inclusions	Northwestern Montana
Cashman Quarry Dactite				Commonly a light grayish white, but may range to a dark gray	Southwestern Montana
Cloverly Quartzite				Ranges from a light gray to gray and a grayish red to a purple.	Southern Montana	Cloverly Formation
Crescent Hill Chert				Primarily homogenous and ranges in color from purple to red or orange, black and green.  Inclusions are commonly present.	Southwestern Montana	Crescent Hills Basalt Formation, Absaroka Supervolcanic Group
Creston Quartzite				Ranges from a pale green to a bluish grey or maroon	Northwestern Montana	Creston Formation
Dean Lake Chert				Ranges from a blackish gray to a tannish gray or bluish gray / black.	Northwestern Montana	Dean Lake Member of the Madison Limestone Formation
Doggett Chert				Variegated or breccia ranging most commonly a light tan or buff to brown.  Less commonly white to light blue or gray, dendritic inclusions are present	Central Montana	Pilgrim Limestone Formation
Dry Creek Quartzite					Montana
Dry Head Agate AKA: Big Horn Agate				Banded and ranges in color from red, pink, yellow, orange, white and brown with swirls and "eyes" present.	South central Montana	Phosphoria Formation
Eastern Petrified Wood AKA: Lake Butte Petrified Wood				Ranges from reds to yellows with inclusions of milky white.  wood grain" and rings are present in the material.  The outer cortex ranges from chalky whites to pale yellows.	Southwestern Montana	Langford Formation
Elk Creek Basalt				Ranges from a dark gray to black	Southwestern Montana	Elk Creek Basalt Member, Washburn Group, Absaroka Supervolcanic
Everson Creek Chert					West central Montana	South Fold - Thrust  Belt
Eyebrow Chert				Ranges in color from tan to orange, red or brown.  Less commonly white to clear or dark brown to black may be present.  Dendritic inclusions are present.	West central Montana	Madison Formation
Flathead Quartzite AKA: Alpreston Quartzite				Ranges light reddish to an orangish red.	Western Montana	Flathead Quartzite Formation
Flaxville Quartzite Gravel				Light gray color	Northern Montana	Flaxville Formation
Fort Union Porcellanite AKA: Powder River Chert				Ranges from most commonly a light gray to a light purple or red.	Southeastern Montana	Fort Union Formation
Gallatin Petrified Forest Wood AKA: Specimen Ridge, Bighorn Peak Petrified Wood				Ranges from reds to yellows with inclusions of milky white.  "Wood grain" and rings are present in the material.	Southwestern Montana	Sepulcher Formation
Garnet Range Quartzite				Greenish gray color	West central Montana	Garnet Range Formation, Missoula Group
Grinnell Argillite				Ranges from a greenish gray or a dark red color	Northwestern Montana	Grinnell Formation of the Belt Series
Gronlid Siltstone				Black in color with a gray shale cortex	North central Montana
Helena Chert					Western Montana	Helena Limestone Formation
Irish Rock Chert				Ranges from a light grayish green to a dark blackish green,  but may range to hues of caramel or red.	Southwestern Montana
Knife River Flint Knife River Chert, Knife River Chalcedony				Ranges in color from a root beer, tea, coffee, or caramel brown	Northeastern Montana	Eocene Golden Valley Formation
Kootenai Argillite AKA: Kootenay Argillite, Kootenie Argillite				Ranges from a light green to a light gray	Northwestern Montana	Kootenai Formation
Lamar Valley Petrified Wood AKA: Amethyst, Mountian, Specimen, Fossil Forest				Ranges from reds to yellows with milky white wood grain, rings are present, outer cortex ranges from chalky whites to pale yellows.	Southwestern Montana	Lamar Formation
Logan Quarry Chert				Light brownish yellow to a medium yellow.  Darker inclusion and veins of quartz / chalcedony may be present.	Southwestern Montana	Jefferson Formation, Madison Group
Madison Chert AKA: Montana Chert				White to a grayish white with black dendritic inclusions.	Southwestern Montana	Madison Limestone Formation
McNamara Argillite				Red and green	West central Montana	McNamara Formation
Miller Peak Argillite				Ranges in color from red to purple (most common) to gray or greenish gray.	West central Montana	Miller Peak Argillite Member of the McNamara Formation
Montana City Jasper				Shades of brown, caramel, and red.	Southwestern Montana
Northeastern Petrified Wood AKA: Bison Peak, Barronette Peak, Mount Hornaday Petrified Wood				Ranges from reds to yellows with inclusions of milky white.  "wood grain" and rings with a cortex ranges chalky whites to pale yellows.	Southwestern Montana	Lamar Formation
Obsidian AKA: Volcanic Glass				Black to black with bands of dark reds (mahogany obsidian) or white flakes (snowflake obsidian)	Montana	Volcanic
Petrified Wood AKA: Agatized Wood, Opalized Wood				Vary in color based on the minerals present during the process	Montana	Varies
Phosphoria Chert AKA: Tosi Chert, Big Horn Chert				Ranges from colors of red, maroon, purple, orangish red, green, black and white.	Southern Montana	Tosi Member of the Phosphoria Formation
Pilcher Quartzite				Ranges from a pale orangish pink to a moderate red.	West central Montana	Pilcher Creek Formation of the Missoula Group
Porcellanite Generic type				Ranges from white to brown or various shades of gray	Montana	Various formations
Powder River Porcellanite					Southeastern Montana	Powder River Formation
Pryor Mountain Jasper				Ranges from brown to red.	Southeastern Montana
Purcell Siliceous Siltstone				Ranges from a khaki green to brown, gray or bluish gray with a rusty weathering common.	Northwestern Montana	Belt Series
Quadrant Quartzite				Ranges from white to a pale yellow or pale pink color.	Southwestern Montana	Quadrant Formation
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	Southeastern Montana	Sentinel Butte formation
Ramshorn Mountain Jasper				Banded with colors of brown and black.	Southwestern Montana
Rhyolite				Gray to grayish black, flow banding may be present alternating from light to darker gray	North America	Volcanic Activity
Rooney Chert				Ranges from white to a light whitish gray.	Southwestern Montana	Rooney Chert Member, Madison Limestone Formation
Schmitt Chert					Southwestern Montana	Mission Canyon Limestone and Lodgepole Limestone formations of the Madison Group
Sentinel Butte Porcellanite				Light green color	East central Montana	Sentinel Butte Shale Member of the Fort Union Formation
South Everson Chert				Mottled or a breccia and ranges in from most commonly a red to a yellowish red or yellow and yellowish brown to brown.	Southwestern Montana
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	Southeastern Montana	Dean Member of the Golden Valley formation
Tom Miner Basin Wood				Ranges from black to tan or brown with white rings or wood grain.  White chalcedony inclusions and reds colors may be present.	Southwestern Montana
Tongue River Silicified Sediment AKA: Tongue River Silica				Grayish brown sediment, pseudoquartzite, or arenaceous chert	Southeastern Montana	Slope / Bullion Creek formation
Tower Region Petrified Wood AKA: Yancy's Forest, Roosevelt Lodge Petrified Wood				Ranges from reds to yellows with inclusions of milky white.  "Wood grain" and rings are present in the material.	Southwestern Montana	Lamar 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
Upper Lamar Petrified Wood AKA: Miller Creek, Cache Creek, Cache Mountain, Abiathar Peak, The Thunderer Petrified Wood				Ranges from reds to yellows with inclusions of milky white.  "Wood grain" and rings are present in the material.  The outer cortex ranges from chalky whites to pale yellows.	Southwestern Montana	Lamar Formation
Vanochen Chert					Montana, Alberta
White River Group Silicate Generic type				Ranges from light to medium gray, to a light brown, pink, blue or lavender with inclusions, splotches,mottling.	Southeastern Montana.	White River Group
Woodhurst Chert Madison Chert variant				Ranges from a dark gray to almost black	Central Montana	Woodhurst Member of the  Madison Limestone Formation