Category: Glaze > Purple
Created 2005-06-02 09:00:00 by Glazy Admin
Categories: Glaze > Purple
Firing Temperature: Δ10
Atmospheres: Reduction
Surface Type: Satin
Transparency: Opaque

From John Britt's book "High-Fire Glazes".

Material Amount Batch Subtotal
Custer Feldspar 50
Silica 21.3
Whiting 8.8
Gerstley Borate 6.9
Dolomite 6.4
Zinc Oxide 4.2
Kaolin (Theoretical) 2.7
Total Base:100.3
Titanium Dioxide 3.5
Tin Oxide 3.2
Copper Carbonate 1.1
Total: 108.1

Percentage Analysis

Ingredient Amount SiO2 Al2O3 B2O3 MgO CaO ZnO K2O Na2O KNaO P2O5 Fe2O3 TiO2 CuO SnO2 LOI
Custer Feldspar5034.258.50.1551.
Gerstley Borate6.
Zinc Oxide4.24.2
Kaolin (Theoretical)
Titanium Dioxide3.53.5
Tin Oxide3.23.2
Copper Carbonate1.10.710.39
100% no LOI 59.19.861.891.688.564.295.141.816.950.010.083.580.723.27

Unity Molecular Formula (UMF)



0.09 Na2O
0.17 K2O
0.16 ZnO
0.46 CaO
0.13 MgO


0.29 Al2O3
0.08 B2O3


2.98 SiO2
0.07 SnO2
0.14 TiO2


0.03 CuO





0.25 : 0.75

SiO2:Al2O3 Chart

Closest 58 neighbors in Glaze > Purple.

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Stull Chart
SiO2:Al2O3 Ratio
SiO2:Al2O3 Ratio 10.14

Similar Base Recipes

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09/2016 Note: This is a new feature. If a recipe material is not listed, that material's data has not yet been added. Some materials only have GHS ratings, while others only have HMIS ratings. Warnings differ between systems and countries. Glazy does not take any responsibility for accuracy of linked SDS information. Contact your ceramics supplier for safety information for your specific materials.
Globally Harmonized System (GHS) Hazardous Materials Identification System (HMIS) SDS Link
Material Pictograms Signal Word Hazard Statements Health Flammability Hazard Protection
Custer Feldspar HarmfulHealth Hazard WARNING May cause damage to lungs through prolonged or repeated inhalation.
Suspected of causing cancer through
prolonged or repeated inhalation.
May cause allergy or asthma symptoms or breathing difficulties if inhaled.
May cause skin or eye irritation.
Silica HarmfulHealth Hazard DANGER From 200-Mesh SDS:
May cause cancer by inhalation.
Causes damage to lungs through prolonged or repeated exposure by inhalation.
* 0 0 E
Whiting Harmful WARNING Causes eye irritation
Gerstley Borate
Dolomite Health Hazard DANGER May cause cancer (Inhalation) 1 0 0 E
Zinc Oxide 0 0 0 *
Kaolin (Theoretical) HarmfulHealth Hazard DANGER SDS for EPK KAOLIN: EPK Kaolin is a naturally occurring mineral, which may contain amounts of crystalline silica
typically 0.1-1.0%, may cause damage to respiratory system through prolonged or repeated
Titanium Dioxide Health Hazard WARNING Suspected of causing cancer
Tin Oxide Harmful WARNING Harmful if swallowed.
Copper Carbonate Harmful WARNING Harmful if swallowed.
Causes skin irritation.
Causes serious eye irritation.