Mineral particles and metals are often present as well.[30][31] Generally, the oil is less fluid than crude oil, becoming pourable at temperatures between 24 and 27 °C (75 and 81 °F), while conventional crude oil is pourable at temperatures between −60 to 30 °C (−76 to 86 °F); this property affects shale oil's ability to be transported in existing pipelines.[30][32][33]