One defining characteristic of no-gem and non-precious rock jewelry and ornamental decoration which people are drawn to is the layers or patterns of material formed when the rock was created. Whether a repetitive pattern of symmetrical balance or an asymmetrical masterpiece, rock layers create their own sense of beauty and appeal. Varying color and material types compressed together in lines and swirls are elements of natural wonder in a rock hound world. It is not always about rarity or materialistic value, but instead it's about what mother nature is capable of creating to some. Agates and agate-like rocks are sought after by collectors by the beauty of polished layers it seems, even more so than perceived scarcity.
Scientifically, layers in specific kinds of rock are very important to determining past events on Earth. In those formations, sediment built up over many thousands of years, and the layers provide an accurate record of what was happening on the surface of the planet at that time; similar to reading the rings of a tree cross-section. For example, in areas near ancient volcano fallout, layers of ash which once blanketed the Earth's surface were buried in time. Analyzing the depth of an ash layer and its proximity to the volcano can tell scientists the scope of an eruption and provide information about environmental differences before and after the event took place.
Much of what we understand about the history of Earth in terms of age and past catastrophic events is by in part attributed to geology examining the formation of rocks and sediment layers. As a rock hound, finding rocks with distinctive layering is attractive on multiple levels. Firstly, there is the beauty of the rock itself from an artistic perspective, and then there is appreciation for natural processes and time required to create the rock. Although the example layered rocks shown are not precious metals or gems, they still retain intrinsic value to this rock hound as reminders of what nature is capable of creating by combining sediments and material.
