black phosphorite nodule stone rock white background

acid agriculture apatite background brachiopod brown closeup collection conglomerate corrosion facing fertilizer fluorapatite fungicide geology glauconite grey heavy high hydroxyapatite isolated macro manure marine material metallurgy mine mineral natural nature nodular object ore pattern phosphate phosphoric phosphorite phosphorous phosphorus preservative rock rough sample sedimentary single solid stone superphosphate surface white