Lonetree Ranch

Prepared by Larry B. Reinhold from various sources

Rocks, Minerals and Fossils that may be Discovered at Rainbow Bible Ranch

The Earth is made of rock, from the tallest mountains to the floor of the deepest ocean. Thousands of different types of rocks and minerals have been found on Earth. Most rocks at the Earth's surface are formed from only eight elements (oxygen, silicon, aluminum, iron, magnesium, calcium, potassium, and sodium), but these elements are combined in a number of ways to make rocks that are very different.

Types of Rocks - Geologists classify rocks in three groups, according to the major Earth processes that formed them. The three rock groups are igneous, sedimentary, and metamorphic rocks. Anyone who wishes to collect rocks should become familiar with the characteristics of these three rock groups.

Igneous Rocks are formed from melted rock that has cooled and solidified. When rocks are buried deep within the Earth, they melt because of the high pressure and temperature; the molten rock (called magma) can then flow upward or even be erupted from a volcano onto the Earth's surface. When magma cools slowly, usually at depths of thousands of feet, crystals grow from the molten liquid, and a coarse-grained rock forms. When magma cools rapidly, usually at or near the Earth's surface, the crystals are extremely small, and a fine-grained rock results. A wide variety of rocks are formed by different cooling rates and different chemical compositions of the original magma. Obsidian (volcanic glass), granite, basalt, and andesite porphyry are four of the many types of igneous rock.

The three rock groups are igneous, sedimentary, and metamorphic rocks.

Sedimentary Rocks are formed at the surface of the Earth, either in water or on land. They are layered accumulations of sediments-fragments of rocks, minerals, or animal or plant material. Temperatures and pressures are low at the Earth's surface, and sedimentary rocks show this fact by their appearance and the minerals they contain. Most sedimentary rocks become cemented together by minerals and chemicals or are held together by electrical attraction; some, however, remain loose and unconsolidated. The layers are normally parallel or nearly parallel to the Earth's surface; if they are at high angles to the surface or are twisted or broken, some kind of Earth movement has occurred since the rock was formed.

Metamorphic rocks form while deeply buried within the Earth's crust. Sometimes sedimentary and igneous rocks are subjected to pressures so intense or heat so high that they are completely changed. The process of metamorphism does not melt the rocks, but instead transforms them into denser, more compact rocks. New minerals are created either by rearrangement of mineral components or by reactions with fluids that enter the rocks. Some kinds of metamorphic rocks--granite gneiss and biotite schist are two examples--are strongly banded or foliated. (Foliated means the parallel arrangement of certain mineral grains that gives the rock a striped appearance.) Pressure or temperature can even change previously metamorphosed rocks into new types.

The process of metamorphism does not melt the rocks, but instead transforms them into denser, more compact rocks.

Quartz in a pure form is sometimes called clear quartz. It is colorless or white and transparent (clear) or translucent. Quartz goes by an array of different names. The most important distinction between types of quartz is that of macrocrystalline (individual crystals visible to the unaided eye) and the microcrystalline or cryptocrystalline varieties (aggregates of crystals visible only under high magnification). The cryptocrystalline varieties are either translucent or mostly opaque, while the transparent varieties tend to be macrocrystalline. Chalcedony is a cryptocrystalline form of silica consisting of fine intergrowths of both quartz, and its monoclinic polymorph moganite. Quartzite is a metaphorphic rock where sandstone has been buried and then subjected to high temperatures and pressure.

Major Varieties of Quartz

Chalcedony - Cryptocrystalline quartz and moganite mixture. The term is generally only used for white or lightly colored material. Otherwise more specific names are used.

Agate - Multi-colored, banded chalcedony, semi-translucent to translucent

Milk Quartz – White, translucent to opaque, may display diasterism

Flint - is a compact microcrystaline quartz. It is found in chalk or marly limestone formations and is formed by a replacement of calcium carbonate with silica. It is commonly found as nodules. This variety was often used in past times to make bladed tools.

Common chert is a variety of chert which forms in limestone formations by replacement of calcium carbonate with silica. This is the most abundantly found variety of chert. It is generally considered to be less attractive for producing gem stones and bladed tools than flint.

Jasper - is a variety of chert formed as primary deposits, found in or in connection with magmatic formations which owes its red color to iron inclusions. Jasper frequently also occurs in black, yellow or even green (depending on the type of iron it contains). Jasper is usually opaque to near opaque.

Fossils

Some of the specimens that one may find are still coated with iridescent mother-of-pearl. They are even impressive when the mother-of-pearl is removed and the surfaces are polished. That brings out the beautiful, delicate patterns of the squiggly sutures that ran between the interior chambers. The patterns look something like coral, or like tiny leaves with frost-tinted edges.

Ammonites - Ammonites were a kind of mollusk, a squid like creature that lived in a chambered shell. The closest living relative of the ammonite is the chambered nautilus. The classic ammonite has a coiled shell that looks like a ram's horn, which is why it was named after the Egyptian god Ammon, who was typically shown wearing such horns.

Baculite - Latin for "walking stick rock" — is essentially a vertical ammonite, resembling a petrified scabbard. Another common ammonite is loosely coiled and looks like a fossilized earthworm or snake, depending on the size. All ammonites raised and lowered themselves in the sea by filling the many chambers inside their shell with either air or water.

Petrified wood is a type of fossil which consists of fossil wood where all the organic marterials have been replaced with minerals, most often a silicate such as quartz. What is so cool is that it retains the original structure of the wood. The petrification process occurs underground, when wood becomes buried under sediment and is initially preserved due to a lack of oxygen. Mineral-rich water flowing through the sediment deposits and replace the plant’s cells as the plant's lignin and cellulose decay away and then a stone mould is formed. In general, wood takes less than 100 years to petrify. The organic matter needs to become petrified before it decomposes completely.

Petrified wood can preserve the original structure of the wood in all its detail, down to the microscopic level. Structures such as tree rings and the various tissues are often observed features.

Other elements found in the water/mud during the fossilizing processfication process give petrified wood a variety of color ranges. Pure quartz crystals are colorless, but when contaminants are added to the process the crystals take on a yellow, red, or other tint. Following is a list of contaminating elements and related color hues:

Carbon- black

Cobalt- green/blue

Chromium - green/blue

Copper - green/blue

Iron oxides - red, brown, and

yellow

Manganese - pink/orange

Manganese oxides - black/yellow

Coral

Concretion of Clams

Casts - the preserved sediment or rock that fills a mold or impression, taking the shape of the once living organism.

Other Rocks and Minerals to find.

Granite – An igneous rock that has formed by the slow cooling within the earth

Shale - a dark, fine-grained sedimentary rock that usually forms in deep, calm water.

Sandstone – A sedimentary rock that has formed due to river or shallow sea sand that has cemented together.

Cone in Cone Concretion

Gypsum Crystals

Geode - a hollow rock or cavity containing inward pointing crystals.

Calcite Crystals

Barite Crystals

Conglomerate - a coarse sedimentary rock that is composed of varying sizes of other rock. Starting a Collection

A good rock collection consists of selected, representative, properly labeled specimens. The collection can be as large or as small as its owner wishes. An active collection constantly improves as specimens are added or as better ones replace poor specimens. A rock collection might begin with stones picked up from the ground near your home. These stones may have limited variety and can be replaced later by better specimens.