Here was a list of marble companies, including West Virginia, that someone had done back in 2001 and posted to the Marble Mansion Board.
KNOWN WEST VIRGINA "SWIRL" MAKERS:
The Akro Agate Company - Akron, OH and Clarksburg WV
The Alley Agate Company/The Lawrence Glass Novelty Company/The Alley Glass Manufacturing Company - Paden City, Sisterville, Pennsboro, and St. Marys, WV
C.E. Bogard & Sons Agate Company/The Bogard Company - Cairo, WV
The Cairo Novelty Company - Cairo, WV
The Champion Agate Company - Pennsboro, WV
The Davis Marble Works - Pennsboro, WV
The Heaton Agate Company - Cairo, WV
The Jackson Marble Company - Tollgate, WV
The Ravenswood Novelty Works - Ravenswood, WV
OTHER KNOWN "SWIRL" MAKERS:
The Alox Manufacturing Company - St. Louis, MO
The Christensen Agate Company - Cambridge, OH
Jabo, Incorporated/Jabo-Vitro, Incorporated - Reno, OH
The Peltier Glass Company - Ottawa, IL
Vacor de Mexico/Mega - Guadalajara, Mexico
OTHER KNOWN WEST VIRGINIA COMPANIES:
Marble King, Incorporated/Berry Pink Industries - St. Marys and Paden City, WV
The Master Glass Company - Bridgeport, WV
The Master Marble Company - Anmoore, WV
The Vitro Agate Company/Gladding-Vitro Agate Company - Parkersburg, WV
OTHER KNOWN SLAG MAKERS:
Iowa City Flint Glass Manufacturing Company - Iowa City, IA
M.F. Christensen and Sons Glass Company - Steubenville, OH
OTHER POSSIBLE SLAG OR "SWIRL" MAKERS:
Mid-Atlantic of West Virginia, Incorporated - Ellenboro, WV
The Nivison-Weiskopf Company - Cincinnati, OH
Playrite Marble and Novelty Company - Ellenboro, WV