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What are magnesium crowns in the Pidgeon process?

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magnesium processing Vapor-deposited magnesium crystals produced from magnesium processing.

In the Pidgeon process, the term "crowns" refers to the magnesium crystals that form during the thermal reduction of calcined dolomite.1

During this process, ground and calcined dolomite is mixed with ferrosilicon and heated within vacuum-sealed, nickel-chromium-steel retorts. As the magnesium vaporizes and travels into the attached condenser systems, it solidifies into these crystalline structures. Once the reaction cycle is complete, these magnesium crowns are manually removed from the condensers for further processing.1