In geology pictures of rocks can be used to help you best determine which of the three major types a particular rock belongs to.
What are rocks with crystals inside called.
Rocks which are completely filled with small compact crystal formations such as agate jasper or chalcedony are called nodules.
Shells tree branches roots and other organic materials often decay away to leave a void for the formation of mineral materials.
The crystals are formed by the filling of vesicles in volcanic and sub volcanic rocks by minerals deposited from hydrothermal.
Igneous metamorphic and sedimentary rocks hold the history of the earth and the materials that will be used to build its future.
Many excellent books and websites have been written to help identify crystals on or within rocks.
Geodes derived from the greek word γεώδης meaning earth like are geological secondary formations within sedimentary and volcanic rocks geodes are hollow vaguely spherical rocks in which masses of mineral matter which may include crystals are secluded.
A crystal or crystalline solid is a solid material whose constituents such as atoms molecules or ions are arranged in a highly ordered microscopic structure forming a crystal lattice that extends in all directions.
The geode at the left and the one at the top of the page are both dugways from utah.
This is a special type of small cavity found in coarse grained igneous rocks like granite especially in late stage settings such as pegmatites miarolitic cavities feature crystals of the same minerals as the rest of the rock the groundmass protruding into them.
All geodes are not created equal the first one is quite hollow but for a nice layer of medium sized blue crystals.
The colors come from the different minerals that flowed through the bubble so many millions of years ago.
Igneous sedimentary or metamorphic.
Crystals with small flat surfaces are said to have facets all crystals have a faceted surface but not all crystals have multiple facets.
These dugway geodes have bands of blue and pink.
Tumbled stones are rocks that have been rounded smoothed and polished in a rock tumbler.
Collect several rock samples with crystals before identifying them.
By comparing your rock sample with photographic examples you can identify key characteristics such as how the rock was formed what minerals and other materials it contains and where the rock may have come from.
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.
The only difference between a geode and a nodule is that a geode has a hollow cavity and a nodule is solid.
How are geodes created.
I bought these rocks from a small etsy shop they claim to have crystals inside when you smash them open.