This is the world's largest cement company, second-largest concrete firm and third-largest gypsum wallboard maker.

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So do buildings materials firms like Chicago-based USG, maker of the popular Sheetrock brand of gypsum wallboard.

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Eagle Materials Inc. is a Dallas-based company that manufactures and distributes cement, gypsum wallboard, recycled paperboard and concrete and aggregates.

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Gypsum wallboard revenue grew almost 52% in the quarter with volumes increasing 24% and the average selling price rising 30%.

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Based in Dallas, Texas, Eagle is a manufacturer and distributor of building material and construction products like cement, gypsum wallboard, recycled paperboard, and concrete and aggregates.

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However, rather than coming from thermite, the metallurgist Professor Sisson thinks the sulphur came from masses of gypsum wallboard that was pulverised and burnt in the fires.

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The reaction creates gypsum that can be sold to companies like wallboard makers.

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