Fire Assay Terms and Terminology

Here are some word or talk/terms of the trade we using in assaying: Annealing – the heating of gold after parting to change its colour from black to gold.
Bead – Particle of gold and silver that is obtained at the end of the cupellation process.
Borax – An acid flux.
Crucible – A bone ash vessel in which the sample and fluxes are melted.
Cupel – A shallow cup which the lead button is oxidized during cupellation.
Cupellation – Process of burning off the lead button.
Feathers – crystals of lead oxide on the edge of the cupel. Indicates that the cupellation worked as it should.
Flux – reagent mixed with a sample that aids in the fusion process.
Freezing of the cupel - A condition in which solid lead oxide or other solids cover the surface of the molten lead in a cupel.
Fusion – Process of heating a charge in a crucible to cause reactions and produce a molten liquid.
Inquartation – The addition of silver to ensure that the bead will part.
Lead button - Metallic lead produced during a fusion and becomes solid in the mould.
Lime - A basic flux.
Litharge – Lead oxide, a basic flux and a source of lead used in fire assay.
Microbalance – A very sensitive balance that weighs beads. 
Mould – An iron cone shaped vessel, which fused materials are poured into.
Muffle – A chamber in a furnace in which fusion and cupellation are carried out.
Opening of the cupel - At the beginning of cupellation when the surface of the lead oxide melts.
Ore – A natural material that came from the earth, that is to be assayed.
Oxidizing agent – An ore or a reagent that supplies oxygen for reactions during the fusion.
Parting – Method of separating gold and silver by dissolving the silver.
Parting acid - Nitric, Hydrochloric and Sulphuric acids.
Parting cup - A porcelain vessel which parting, rinsing and annealing of the gold takes place.
Reducing agent – An ore or reagent that accepts oxygen during the fusion which helps in the formation of the metallic lead.
Reducing Power – The ratio of lead reduced during the fusion to the weight of the reducing agent added.
Scorification – An oxidizing fusion of a sample with lead and borax in a shallow dish.
Slag – A fused mixture of non-metallic sample ingredients and fluxes, usually contains silicates.
Soda ash - Sodium carbonate, which is a basic flux.