Shells tree branches roots and other organic materials often decay away to leave a void for the formation of mineral materials.
Rocks with white crystals inside.
Collect several rock samples with crystals before identifying them.
Finding a cool looking rock and then dissolving the calcite out of it with white vinegar to expose crystals in one week.
Typically the inclusion of clay gives jasper a yellowish white to gray tone.
Igneous rock is created by volcanic activity forming from magma and lava as they cool and harden.
Sedimentary rocks such as limestone or shale are hardened sediment with sandy or clay like layers strata they are usually brown to gray in color and may have fossils and water or wind marks.
It was once believed that rock crystals were ice too frozen to melt.
If no crystals form the result will be natural glass.
Dalmatian jasper a fine grained dense quartz called chalcedony jasper is found in a variety of colors.
Igneous rock may form crystalline structures as it cools giving it a granular appearance.
Geodes in sedimentary rocks are usually found in limestones dolomites and calcareous shale in these deposits a gas filled void can serve as the opening for geode formation.
Crystals with small flat surfaces are said to have facets all crystals have a faceted surface but not all crystals have multiple facets.