A test for fracture requires that you break the sample, the streak test requires that you rub a sample across a piece of tile, and the test for hardness requires that you scratch the sample. Luster, on the other hand, describes how the sample looks. Fracture results in an irregular surface rather than a well-defined, smooth plane. Most minerals do not show cleavage when broken, but do show fracture. Rapid cooling does not result in sufficient time for larger crystals to form, so igneous rocks that form by rapid cooling will have a fine texture with small crystals.
Sediments are accumulations of silt, sand, or gravel that settle out the atmosphere or out of water.
Marble is a metamorphic rock formed when calcite crystals were recrystallized from limestone, again a condition that would probably destroy any fossils. Shale, on the other hand, is a sedimentary rock that formed from sediments of silt or clay in a process that would help preserve evidence of former life. Sandstone, as the name implies, is a sedimentary rock formed from sand that has been consolidated into solid rock. Conglomerate is a sedimentary rock formed from sediment with size ranges over 256 mm. Quartzite is a metamorphic rock formed from recrystallized quartz-rich sandstone.