Limestone Specifications (Composition) + Example (PDF)
Iron (III) oxide or hematite (Fe 2 O 3) Sulphate (SO 3) Phosphorus (P 2 O 5) As mentioned, the main elements in the chemical analysis of Limestone are CaCO3 and CaO, but like other minerals, Limestone contains trace impurities like SiO 2, Al 2 O 3, etc. The most workable amount of SiO 2 should be under 1% that our Limestone has 0.94% of Silica.