A crystal is a solid where the atoms form a periodic arrangement. (Quasicrystals are an exception, see below). Not all solids are crystals. For example, when liquid water starts freezing, the phase change begins with small ice crystals that grow until they fuse, forming a polycrystalline structure.

four types

A face-centered cubic crystal structure will exhibit more ductility (deform more readily under load before breaking) than a body-centered cubic structure. The bcc lattice, although cubic, is not closely packed and forms strong metals. Alpha-iron and tungsten have the bcc form.

Amorphous solids have two characteristic properties. When cleaved or broken, they produce fragments with irregular, often curved surfaces; and they have poorly defined patterns when exposed to x-rays because their components are not arranged in a regular array. An amorphous, translucent solid is called a glass.

Nearly all minerals can form crystals when the chemical structure repeats. A rock is any naturally occurring solid mass or aggregate of various minerals. Even though rocks are composed of minerals, and in most cases also microscopic crystals, they are not a crystal or mineral themselves.

Are crystals worth any money? Aside from its clearness making the crystal more valuable, there are certain colors you will find in quartz. Generally speaking of Arkansas quartz, the lack of color, rather than being milky, makes the value of the crystal increase.

Many rocks have crystals embedded on their surfaces, within the rocks or are considered to be crystals. Crystals have flat surfaces which can be either large or small. Crystals with small flat surfaces are said to have “facets.” All crystals have a faceted surface, but not all crystals have multiple facets.

The term geode is derived from the Greek word Geoides which means “earthlike.” A geode is a round rock which contains a hollow cavity lined with crystals. Rocks which are completely filled with small compact crystal formations such as agate, jasper or chalcedony are called nodules.

Four diamonds have been found within the current boundaries of Virginia: – at the Vaucluse Mine in Orange County (1836) A fifth diamond was found in 1928 on Rich Creek near Peterstown, West Virginia, just across the state border from Giles County. It is known as the “Punch Jones” diamond.

Contents

• 2.1 Agate.
• 2.2 Amethyst.
• 2.3 Beryl.
• 2.4 Carbuncle.
• 2.5 Carnelian.
• 2.6 Chalcedony.
• 2.7 Chodchod.
• 2.8 Chrysolite.

Jasper. Tiger’s Eye. Aventurine. Black Obsidian (FYI: can break in EXTREME cold or hot water temperatures)

You cannot identify an agate or jasper specimen by color alone. Each of these minerals come in a wide array of colors, but it the translucency (or lack of) that determines what type of mineral you actually have. Jaspers are commonly found in red, green, yellow, tan, brown, and even purple.

red

In general, agate values are quite modest. Their prices reflect mainly labor and artistry rather than the value of the material itself. Agates of large size or with particularly distinctive, fine, or landscape-like color patterns are at a premium.

An opaque, semi-precious stone, an agate would be familiar to almost any American, even if the mineral’s name isn’t. Agates vary in color from bright blue to glowing amber and deep black. They yield beautiful striped patterns when cut and polished.