A gemstone is usually a mineral, but it is one that has formed crystals and then been cut and polished professionally to be made into a piece of jewelry. The study of gemstones is called gemology. This is a type of mineralogy the study of minerals that is the study of the physical properties seen by the naked eye and also in magnification of the stone.
The evaluation of a gemstone is based on the value of the gem given by a gemologist, one who studies these gems. It is usually a decorative and very beautiful stone, and it is also usually very valuable as well.
Gemstones are usually measured by their hardness, size, and rarity. Unpolished gemstones simply look like ordinary rocks; cutting and polishing allows them to have brilliance and sometimes color leading to their value that can't be found in other types of stones.
Gemstones are usually classified as semiprecious and precious stones. Some semiprecious gemstones include amethyst, garnet, citrine, turquoise, and opal. Precious gemstones include diamond, emerald, ruby, and sapphire. The scientific term for rocks is petrology, and understanding them is crucial for understanding the formation and mineral makeup of the earth.
Rocks are made from minerals and can come in every size: They can be tiny pebbles or mountains big enough on which to climb or drive. Rocks do not have a special chemical or mineral makeup. While most rocks are not cut or polished to be used as gemstones, some rocks, including lapis lazuli, are classified as gems. Minerals occur naturally within the earth's surface and are solid formations. They are defined by their shape and their crystalline makeup.
When a mineral is deemed to have aesthetic value and is faceted like a jewel, this kind of rock is called a gemstone rather than a crystal. Crystals such as fluorite and quartz are usually categorized under what rockhounds typically consider semiprecious stones. Nevertheless, some semiprecious, such as ammolite or red beryl, are very rare. Check the best of them here:. Here are some of the most interesting forms of minerals and crystals that you can find and some intriguing qualities of them:.
Fluorite comes in a wide range of colors, but pure fluorite is completely clear. The sunstone was a crystal that was used by the ancient Vikings as a way to navigate their way to the New World and is formed from a specific crystalline form of calcite.
Iceland spar refracts light twice, allowing navigators to line it up with the sun and the horizon to find their way across the ocean. Quartz is most famous for its ability to generate electricity, which is why it has been included in watchmaking and clockmaking activities for hundreds of years. Quartz crystals are also the mineral that scientists used to analyze and eventually decipher the shape of atomic crystalline structures.
The interesting thing about autunite other than its weird scale-like shape and yellow coloring is that it is luminescent under ultraviolet lighting, which is a fancy way of saying it glows under blacklights. This fluorescent glow is caused by the subatomic movement of the autunite participles in response to the energy being delivered by ultraviolet rays. One odd property that some crystals and minerals contain is the ability to change color according to their exposure to light.
Hackmanite is one such crystal, appearing to be pale blue during the day but a deep purple color at night. It also glows with a bright orange-red flare in ultraviolet light. Hematite is an interesting material, and while many people may incorrectly define it as a crystal due to its smooth appearance and mirror-like surface and the fact that it is often carved into crystalline structures , this stone is a mineral.
Hematite is a form of iron oxide and has the unique property of being magnetic, which makes it a popular healing stone in metaphysical circles. Many rockhounds focus their collections on shiny crystals and gemstones, but many kinds of specialized rocks can also add interest and personality to your set. Here are some special rocks you might consider adding to your collection of rocks and minerals:.
Geodes are crystal caves that are formed from bubbles in volcanic rock or burrows, mud balls, or tree roots in sedimentary rock. Over time, the organic aspects of these caves rot away, leaving a hollow in the sedimentary rock that becomes crystallized.
Geodes are often displayed either sliced in half to display the crystal hollow inside or sliced and polished to make them translucent. Petrified wood is a type of fossil and occurs when vegetation such as a tree trunk becomes mineralized, often taking on the appearance of a crystalline structure.
Unlike some special rock formations, petrified wood is not that rare. It is found in most locations where volcanic activity has occurred at some point in geological history. Amber is a tree sap that has become mineralized for hundreds of years and is often used as a semiprecious stone in jewelry.
Amber is most famous for capturing prehistoric insects and other creatures inside of it, effectively freezing them in time. Amber that contains organic material such as an insect is typically much more expensive than plain amber, and it can come in several varying shades from a light golden color to almost red coloration. Fossils occur when organic material becomes trapped in rock matter and decomposes, either leaving a hollow and a perfect imprint or petrified bone in its place.
The fossil record is the only reason that humanity currently knows that dinosaurs ever existed. There are many small fossils of everything from prehistoric shark teeth to trilobites that are popular among rockhounds. Some of these unique rock formations form the focal points for many a rock and gem collection. Titanium is one of the most abundant and toughest metals on Earth. It is used extensively in human body repair. Tungsten is a metal that is stronger than steel and a high melting temperature.
It is also used to make saw blades and used in welding. Uranium is a highly radioactive element. It is used in cancer treatments, X-rays, military weapons and fuel for the space shuttle. Vanadium is found in many foods and helps bones grow. It is useful in regulating blood sugar in diabetics and helps grow muscles for bodybuilders. It is used in wastewater cleanup and since it can absorb ammonia, it is used in kitty litter and reducing other animal smells. Zinc [image left] is essential for a healthy life.
Zinc deficiency can cause rashes, diarrhea, impaired taste and eye problems. It is used to macular degeneration, diabetes and the common cold.
Some examples of minerals mined here in Ireland are: Gypsum Gypsum is an evaporite mineral and the most common Sulphate mineral in the world. It is used widely in the construction industry in the form of plasterboard and wet plaster. Gypsum Gypsum is a very soft mineral with a variety of uses, most commonly in drywall, also known as sheet rock. It is also used as a fertilizer and road construction. It is mined in areas of Co. Copper Copper is a soft, malleable, and ductile metal with very high thermal and electrical conductivity.
It is widely used in electronics industry especially for use in wires. Copper is a common metal throughout the world.
It is used for currency, jewelry, plumbing and to conduct electricity. It is a soft, orange-red metal. Copper has previously been mined in Co. Lead and Zinc, and sometimes silver, are usually found occurring together. Ireland has a long histroy of minig lead and zinc with some of the larges mine Europe recently operating here; Lisheen Mine Co. Tipperary and Tara Mine Co. Meath and historically Silvermines Co. Precious metals are rare, naturally occurring metallic chemical elements of high economic value.
Chemically, they tend to be less reactive than most elements. They are usually ductile and have a high lustre. In history precious metals were important as currency but are now regarded mainly as investment and industrial commodities. The main examples of precious metals are Gold, Silver and Platinum. Some examples of precious metals found in Ireland are; 1.
Gold Gold is a valuable, yellow metal. Gold is usually found in metamorphic rock. It is found in underground veins of rock where the inside of the Earth heats the water that flows through the rock. Gold has been important all throughout history, it was used in important events by the ancient Egyptians and was important in Bronze Age Ireland.
Due to both it beauty and its durability it is regularly used in jewellery and as a form of currency. Have you ever wondered about the difference between a gemstone, a rock and a mineral? Did you know that there has been much debate over what constitutes a gemstone?
Since gemstones are used in jewelry making, they have a clear aesthetic and economic value. In turn, this value has become the basic characteristics of a gemstone, rather than its internal structure.
Mineralogy, the science of minerals, teaches us that minerals are formed as a result of geological processes, and are, therefore, naturally occurring inorganic substances. They have a specific chemical and physical composition featuring a highly ordered atomic and typically crystalline structure. You can identify a specific mineral based on seven factors: its color, luster, streak, fracture, cleavage, hardness and crystal form.
While minerals have thousands of forms, from pure elements to complex silicates, rocks are divided into three type: igneous, sedimentary and metamorphic.
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