CAUTION: Some of these materials are toxic in their dry unfired or fired state. You should always use a dust mask when working with these materials. We have an inexpensive, Toxic Dust Mask available. Also Material Safety Data Sheets are available on request or can be downloaded from MSDS Search. These materials have always been potentially harmful, so let’s get serious about safe handling. custer-minspar Custer Feldspar (potash)- 1pound custer-1$1.70 Minspar (soda)- 1pound minspar-1$1.70 Kona F4 (soda), 1 pound F4-1$1.70 G-200 (potash) 1 pound g200-1$1.70 5 pounds custer-5$2.75 5 pounds minspar-5$2.75 5 - pounds f4-5$2.25 5 pounds g200-5$2.40 10 pounds custer-10$5.00 10 pounds minspar-10$5.00 10 - pounds f4-10$4.30 10 - pounds g200-10$4.60 25 pounds custer-25 25 pounds minspar-25 25 - pounds f4-25$10.50 25 - pounds g200-25$11.25 50 pounds custer-50$14.00 50 pounds minspar-50$11.00 50 - pounds f4-50$20.00 50 - pounds g200-50$21.50 100 pounds custer-100$25.00 100 pounds minspar-100$19.00 100 pounds f4-100$38.00 100 pounds g200-100$41.00 500 pounds custer-500$115.00 500 pounds minspar-500$92.50