What is a Crystal??
Many solids and some crystalline liquids have a regular, repeating, three-dimensional arrangement of atoms known as a crystal structure or crystal lattice. In contrast, an amorphous solid is a type of solid material, such as glass, that lacks such a long-range repeating structure. Many of the physical, optical, and electrical properties of crystalline solids or liquids are closely related to crystal structure. The repeating units of a crystalline structure, which are made up of small boxes or other three-dimensional shapes, are referred to as “cells.” Many of these cells are grouped together in a repeating, orderly structure to make up the overall structure. The crystal structure of a give crystalline material can affect many of that material’s overall properties. It is one of the major defining factors affecting the optical properties of the material, for instance. Crystal structure also significantly affects the reactivity of the crystalline material, as it determines the arrangement of reactive atoms on the outside edges and faces of the crystalline solid or liquid. Other important material traits, including electrical and magnetic properties of some materials, are also determined largely by crystal structure. Mineralogists, crystallographers, chemists, and physicists often study crystalline materials in laboratory settings. Some simple aspects of crystal structures can be determined through simple geometric measurements, but various methods based on the diffraction of x-rays, neutrons, electrons, or other particles allow for much easier and more accurate determinations of structure. Some researchers are only concerned with determining the structure of a given crystalline material while others are more interested in determining how that structure connects to the material’s other properties. Still other researchers are interested in finding useful applications for various materials based on their structures, and some even try to synthesize new crystalline solids and liquids based on the expected properties of their desired structures. It should be noted that, though theoretical crystalline materials are composed of a perfect and consistent series of repeated units, real crystals tend to have flaws. These flaws are, in most cases, simply irregularities in the otherwise regular crystal structure. In some cases, this occurs when one atom takes a different place in a given crystal structure than it normally would. The different properties of this atom can have substantial impacts on how the crystal’s structural units arrange themselves around it. Likewise, the defects or irregularities of real crystals can have substantial impacts on the overall properties of the crystalline material.
What is a Mineral??
A mineral is a naturally occurring substance that is solid and stable at room temperature, representable by a chemical formula, usually abiogenic, and has an ordered atomic structure. It is different from a rock, which can be an aggregate of minerals or non-minerals, and does not have a specific chemical composition. The exact definition of a mineral is under debate, especially with respect to the requirement a valid species be abiogenic, and to a lesser extent with regards to it having an ordered atomic structure. The study of minerals is called mineralogy. There are over 4,900 known mineral species; over 4,660 of these have been approved by the International Mineralogical Association (IMA). The silicate minerals compose over 90% of the Earth’s crust. The diversity and abundance of mineral species is controlled by the Earth’s chemistry. Silicon and oxygen constitute approximately 75% of the Earth’s crust, which translates directly into the predominance of silicate minerals. Minerals are distinguished by various chemical and physical properties. Differences in chemical composition and crystal structure distinguish various species, and these properties in turn are influenced by the mineral’s geological environment of formation. Changes in the temperature, pressure, and bulk composition of a rock mass cause changes in its mineralogy; however, a rock can maintain its bulk composition, but as long as temperature and pressure change, its mineralogy can change as well.
Geodes are geological secondary structures which occur in certain sedimentary and volcanic rocks.
Zoisite, first known as saualpite, after its type locality, is a calcium aluminium hydroxy sorosilicate belonging to the epidote group of minerals. Its chemical formula is Ca2Al3(SiO4)(Si2O7)O(OH).
Moonstone is a variety of the feldspar-group mineral orthoclase. During formation, orthoclase and albite separate into alternating layers.
Sulfur or sulphur (see spelling differences) is a chemical element with symbol S and atomic number 16. It is an abundant, multivalent non-metal.
Sodalite is a rich royal blue tectosilicate mineral widely enjoyed as an ornamental gemstone. Although massive sodalite samples are opaque, crystals are usually transparent to translucent.
A crystal dendrite is a crystal that develops with a typical multi-branching tree-like form. Dendritic crystal growth is very common and illustrated by snowflake formation and frost patterns on a window.
Obsidian is a naturally occurring volcanic glass formed as an extrusive igneous rock. It is produced when felsic lava extruded from a volcano cools rapidly with minimum crystal growth.
All minerals have the ability to reflect light. That is what makes them visible to the human eye. Some minerals have an interesting physical property known as “fluorescence”.
Jasper is an opaque rock of virtually any color stemming from the mineral content of the original sediments or ash. Patterns arise during the consolidation process forming flow and depositional patterns in the original silica rich sediment or volcanic ash.
Chrysocolla has a cyan (blue-green) color and is a minor ore of copper, having a hardness of 2.5 to 3.5.
Gold is a chemical element with symbol Au (from Latin: aurum) and atomic number 79. In its purest form, it is a bright, slightly reddish yellow, dense, soft, malleable and ductile metal.
Silver is a chemical element with symbol Ag (Greek: άργυρος árguros, Latin: argentum, both from the Indo-European root *h₂erǵ- for “grey” or “shining”) and atomic number 47.
Aquamarine (from Latin: aqua marina, “water of the sea”) is a blue or cyan variety of beryl. It occurs at most localities which yield ordinary beryl. The gem-gravel placer deposits of Sri Lanka contain aquamarine.
Aragonite is a carbonate mineral, one of the two common, naturally occurring, crystal forms of calcium carbonate, CaCO3 (the other form being the mineral calcite).
Celestine or celestite (SrSO4) is a mineral consisting of strontium sulfate. The mineral is named for its occasional delicate blue color. Celestine is the principal source of the element strontium, commonly used in fireworks and in various metal alloys.
Hematite, also spelled as haematite, is the mineral form of iron(III) oxide (Fe2O3), one of several iron oxides. Hematite crystallizes in the rhombohedral lattice system, and it has the same crystal structure as ilmenite and corundum.
Jasper, an aggregate of microquartz and/or chalcedony and other mineral phases, is an opaque, impure variety of silica, usually red, yellow, brown or green in color; and rarely blue.
Quartz is a hard crystalline mineral which is found abundantly all over the Earth in a variety of forms.
Silicon carbide (SiC), also known as carborundum /kɑrbəˈrʌndəm/, is a compound of silicon and carbon with chemical formula SiC. It occurs in nature as the extremely rare mineral moissanite.
Copper is commonly used in jewelry, and folklore says that copper bracelets relieve arthritis symptoms.
Vanadinite is a mineral belonging to the apatite group of phosphates, with the chemical formula Pb5(VO4)3Cl.
Bornite has a brown to copper-red color on fresh surfaces that tarnishes to various iridescent shades of blue to purple in places. Its striking iridescence gives it the nickname peacock copper or peacock ore.
Herkimer diamond is a generic name for a double-terminated quartz crystal discovered within exposed outcrops of dolostone in and around Herkimer County, New York and the Mohawk River Valley.
Agates are a type of chalcedony, a milky form of quartz, that appears in a striking banded formation that people have found aesthetically pleasing for centuries.
Labradorite can display an iridescent optical effect (or schiller) known as labradorescence.
Septarian is generally a combination of Aragonite, Calcite and volcanic ash from Utah.
Dragon Eggs are a form of septarian from Madagascar with volcania ash and aragonite.
Amber is fossilized tree resin (not sap), which has been appreciated for its color and natural beauty since Neolithic times. Much valued from antiquity to the present as a gemstone, amber is made into a variety of decorative objects.
Selenite, satin spar, desert rose, and gypsum flower are four varieties of the mineral gypsum; …
Calcite, or calcium carbonate, is one of the most common minerals on earth.
Bismuth is a chemical element with symbol Bi and atomic number 83. Bismuth, a pentavalent post-transition metal, chemically resembles arsenic and antimony.
Amethyst is a beautiful stone that is in the quartz family.
Citrine is a beautiful gemstone that has become quite popular over the last few decades.
Fluorite is a mineral with a veritable bouquet of brilliant colors.
Peridot, pronounced Pear-ih-doe is a wonderful gemstone that is very popular for its olive green hue.
Tourmalines are one of the most intricate of all the gemstones and minerals found in the world is Tourmaline.
Garnets are a group of neosilicates with chemical elements containing calcium, magnesium and iron.
Topaz is a wonderful gemstone that is extremely popular and found in many regions around the world.
Diamonds are formed from pure carbon, most were formed hundreds of millions of years ago deep within the earth’s crust.
This gemstone is found all over the world; however the precious variety of Opal is usually mined in one specific spot in the world; Southern Australia.
Emeralds are highly valued, deep green gems, deriving their color from chromium.
One of the more colorful gemstones in the world are Sapphires.
Pyrite: Fool’s Gold
The mineral pyrite, or iron pyrite, is an iron sulfide with the formula FeS2.
The pink color of rhodochrosite is caused by the element manganese…
Jade is a stone valued for its beauty and utility.
Hemimorphite is a sorosilicate mineral which has been mined from days of old from the upper parts of zinc and lead ores, chiefly associated with smithsonite.
Turquoise is a blue-green mineral, a copper aluminum phosphate, valued for its rarity and unique hue, and widely used as an ornamental stone.
Sphalerite is an important ore of zinc and can make a rather attractive cabinet specimen as well.
Galena is the major source of lead ore, and Missouri is the top producer of lead in the United States.
Azurite is a copper carbonate mineral. The chemical formula results from the oxidation of copper sulfides.
Malachite is a popular stone which has dark and light green banded areas, and these patterns give the stone its unique ornamental look unlike that of any other gemstone.