{"product_id":"manganese-carbonate-rmmancar","title":"Manganese Carbonate","description":"\u003cp\u003e\u003cstrong\u003eFor browns, plum purples and metallic bronze effects in glazes, and for darker clay bodies.\u003c\/strong\u003e\u003c\/p\u003e\n\u003cdiv class=\"rm-testing-statement\" style=\"border:2px solid #8a5a00;border-radius:6px;padding:12px 16px;margin:16px 0;background:#fdf6e3;\"\u003e\u003cp style=\"margin:0;\"\u003e\u003cstrong\u003eYou must test before you use it, at any scale.\u003c\/strong\u003e Raw materials, mined or man-made, are not consistent. Color, strength, particle size and chemistry can change from one bag to the next and from one supplier to another, even when the name on the bag stays the same. Before you use this material in a glaze, slip or clay body of any size, mix a small test batch, fire it on your own clay in your own kiln, and check the results.\u003c\/p\u003e\u003c\/div\u003e\n\u003ch3\u003eWhat it is\u003c\/h3\u003e\n\u003cp\u003eA pale pink powder. Manganese gives browns and plum purples in glazes, and at high amounts metallic bronze or black surfaces. It also darkens and speckles clay bodies. The carbonate is the fine-grained form, so it mixes in more evenly than manganese dioxide.\u003c\/p\u003e\n\u003ch3\u003eGetting started\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eStart at 2 to 4% (2 to 4 grams per 100 grams of dry glaze). Most glazes use 6% or less.\u003c\/li\u003e\n\u003cli\u003eGlazes high in sodium or potassium push it toward purple; most others give browns.\u003c\/li\u003e\n\u003cli\u003eMetallic glazes use much more manganese and need extra care. Read the safety notes first.\u003c\/li\u003e\n\u003cli\u003eAlways fire with kiln ventilation.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eFor glaze formulators\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eManganese carbonate, MnCO₃. Loses about 38% of its weight as gas in firing.\u003c\/li\u003e\n\u003cli\u003e1 part MnO₂ ≈ 1.3 parts MnCO₃ for the same manganese.\u003c\/li\u003e\n\u003cli\u003eFiner than manganese dioxide, so fewer specks. The gas it gives off can cause blistering at higher amounts.\u003c\/li\u003e\n\u003cli\u003eWith iron: browns. With iron and cobalt: blacks.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eSafety\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eManganese gives off fumes during firing.\u003c\/strong\u003e Repeated breathing of manganese fumes or dust can damage the nervous system. Vent your kiln to the outside and stay out of the kiln room while it fires.\u003c\/li\u003e\n\u003cli\u003eWear a NIOSH-approved respirator (N95 or better) and gloves when handling it dry. Clean up with a wet sponge, not a broom.\u003c\/li\u003e\n\u003cli\u003eAvoid high-manganese glazes on food surfaces, and have functional ware lab-tested before you sell it.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eSizes \u0026amp; pricing\u003c\/h3\u003e\n\u003ctable style=\"width:100%;max-width:520px;border-collapse:collapse;border:0;margin:0 0 14px;font-variant-numeric:tabular-nums;line-height:1.35;\"\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth style=\"padding:0 0 6px;border:0;border-bottom:2px solid #d9d0c4;background:transparent;font-size:12px;letter-spacing:.06em;text-transform:uppercase;font-weight:600;color:#6b6259;text-align:left;width:40%;\"\u003eSize\u003c\/th\u003e\n\u003cth style=\"padding:0 0 6px;border:0;border-bottom:2px solid #d9d0c4;background:transparent;font-size:12px;letter-spacing:.06em;text-transform:uppercase;font-weight:600;color:#6b6259;text-align:right;padding-left:12px;\"\u003ePrice\u003c\/th\u003e\n\u003cth style=\"padding:0 0 6px;border:0;border-bottom:2px solid #d9d0c4;background:transparent;font-size:12px;letter-spacing:.06em;text-transform:uppercase;font-weight:600;color:#6b6259;text-align:right;padding-left:12px;\"\u003ePer lb\u003c\/th\u003e\n\u003cth style=\"padding:0 0 6px;border:0;border-bottom:2px solid #d9d0c4;background:transparent;font-size:12px;letter-spacing:.06em;text-transform:uppercase;font-weight:600;color:#6b6259;text-align:right;padding-left:12px;\"\u003e\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:left;\"\u003e1 lb\u003c\/td\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:right;padding-left:12px;\"\u003e$42.20\u003c\/td\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:right;padding-left:12px;color:#6b6259;\"\u003e$42.20\u003c\/td\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:right;padding-left:12px;\"\u003e\u003ca href=\"\/cart\/add?id=45105272815938\u0026amp;quantity=1\" style=\"color:#2340a8;font-weight:600;font-size:13px;text-decoration:none;white-space:nowrap;\"\u003eAdd to cart\u003c\/a\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:left;\"\u003e5 lb\u003c\/td\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:right;padding-left:12px;\"\u003e$194.75\u003c\/td\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:right;padding-left:12px;color:#6b6259;\"\u003e$38.95\u003c\/td\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:right;padding-left:12px;\"\u003e\u003ca href=\"\/cart\/add?id=67286164636019\u0026amp;quantity=1\" style=\"color:#2340a8;font-weight:600;font-size:13px;text-decoration:none;white-space:nowrap;\"\u003eAdd to cart\u003c\/a\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:left;\"\u003e10 lb\u003c\/td\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:right;padding-left:12px;\"\u003e$373.50\u003c\/td\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:right;padding-left:12px;color:#6b6259;\"\u003e$37.35\u003c\/td\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:right;padding-left:12px;\"\u003e\u003ca href=\"\/cart\/add?id=67286164668787\u0026amp;quantity=1\" style=\"color:#2340a8;font-weight:600;font-size:13px;text-decoration:none;white-space:nowrap;\"\u003eAdd to cart\u003c\/a\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:left;\"\u003e25 lb\u003c\/td\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:right;padding-left:12px;\"\u003e$892.50\u003c\/td\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:right;padding-left:12px;color:#6b6259;\"\u003e$35.70\u003c\/td\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:right;padding-left:12px;\"\u003e\u003ca href=\"\/cart\/add?id=67286164701555\u0026amp;quantity=1\" style=\"color:#2340a8;font-weight:600;font-size:13px;text-decoration:none;white-space:nowrap;\"\u003eAdd to cart\u003c\/a\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:left;font-weight:700;\"\u003e55 lb bag\u003c\/td\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:right;padding-left:12px;font-weight:700;\"\u003e$1,784.50\u003c\/td\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:right;padding-left:12px;font-weight:700;\"\u003e$32.45\u003c\/td\u003e\n\u003ctd style=\"padding:7px 0;border:0;border-bottom:1px solid #e6dfd5;background:transparent;text-align:right;padding-left:12px;\"\u003e\u003ca href=\"\/cart\/add?id=67286164734323\u0026amp;quantity=1\" style=\"color:#2340a8;font-weight:600;font-size:13px;text-decoration:none;white-space:nowrap;\"\u003eAdd to cart\u003c\/a\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cdiv style=\"max-width:520px;margin:0 0 12px;padding:12px 14px;border-radius:8px;background:#eef3ee;border:1px solid #d6e3d7;\"\u003e\n\u003cp style=\"margin:0 0 6px;\"\u003e\u003cstrong\u003eFull bags mix and match.\u003c\/strong\u003e Every full bag in your order, of any raw material, adds up. That total sets the price of every bag. Smaller sizes don't count.\u003c\/p\u003e\n\u003cp style=\"margin:0;\"\u003eThis bag's price stays the same at every level, but it still counts toward your full-bag total.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cp style=\"margin:0;font-size:13px;color:#6b6259;\"\u003ePrices from our October 23, 2026 price list.\u003c\/p\u003e","brand":"Sheffield Pottery","offers":[{"title":"1 Pound","offer_id":45105272815938,"sku":"RMMANCAR","price":42.2,"currency_code":"USD","in_stock":true},{"title":"5 Pounds","offer_id":67286164636019,"sku":"RMMANCAR-5","price":194.75,"currency_code":"USD","in_stock":true},{"title":"10 Pounds","offer_id":67286164668787,"sku":"RMMANCAR-10","price":373.5,"currency_code":"USD","in_stock":true},{"title":"25 Pounds","offer_id":67286164701555,"sku":"RMMANCAR-25","price":892.5,"currency_code":"USD","in_stock":true},{"title":"55 Pounds","offer_id":67286164734323,"sku":"RMMANCAR-55","price":1784.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0677\/5508\/2050\/files\/1200px-Manganese_28II_29-carbonate-sample_9f72cc3e-8d78-4446-94a1-a38c0d1c4435.jpg?v=1791876107","url":"https:\/\/www.sheffield-pottery.live\/products\/manganese-carbonate-rmmancar","provider":"Sheffield Pottery Inc.","version":"1.0","type":"link"}