|
Ruby Matondang
A ruby is a pinkish red to blood-red colored gemstone, a variety of the mineral corundum (aluminium oxide). Ruby is one of the most popular traditional jewelry gems and is very durable. Other varieties of gem-quality corundum are called sapphires. Ruby is one of the traditional cardinal gems, alongside amethyst, sapphire, emerald, and diamond. The word ''ruby'' comes from ''ruber'', Latin for red. The color of a ruby is due to the element chromium. Some gemstones that are popularly or historically called rubies, such as the Black Prince's Ruby in the British Imperial State Crown, are actually spinels. These were once known as "Balas rubies". The quality of a ruby is determined by its color, cut, and clarity, which, along with carat (mass), carat weight, affect its value. The brightest and most valuable shade of red, called blood-red or pigeon blood, commands a large premium over other rubies of similar quality. After color follows clarity: similar to diamonds, a clear stone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dodoma Region
Dodoma Region (''Mkoa wa Dodoma'' in Swahili language, Swahili) is one of Tanzania's 31 administrative Regions of Tanzania, regions. The regional capital is the city of Dodoma. The region is located in central Tanzania, it is bordered by Singida Region to the west; Manyara Region to the north; Iringa Region to the south; and Morogoro Region to the east. Dodoma Region hosts the nation's capital city with where the legislative assembly or Politics of Tanzania#Legislative_branch, Bunge is based. Dodoma Region also hosts one of the largest University in Tanzania, University of Dodoma. The regiom is sole home of the Tanzanian wine industry, which is the second largest wine industry on the continent after South Africa. According to the 2012 national census, the region had a population of 2,492,989. History Dodoma's name derives from the Gogo people, Gogo word, ''Idodomya'', the location of an elephant's sinking. The city of Dodoma where the region gets it's name, is the largest city ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Black Prince's Ruby
The Black Prince's Ruby is a large, irregular cabochon red spinel weighing set in the cross pattée above the Cullinan II diamond at the front of the Imperial State Crown of the United Kingdom. The spinel is one of the oldest parts of the Crown Jewels of the United Kingdom, with a history dating back to the middle of the 14th century. It has been in the possession of England's rulers since it was given in 1367 to its namesake, Edward of Woodstock (the "Black Prince"). The stone is believed to have originated from the Badakhshan mines in present day Afghanistan and Tajikistan, the principal source of large spinel gems in the Middle Ages. Spinel All red gemstones used to be referred to as rubies or "balas rubies". It was not until 1783 that spinels were chemically differentiated from rubies. They both have aluminium, oxygen, and a little chromium, but spinels also have magnesium, which rubies lack. History Don Pedro of Seville The Black Prince's Ruby dates back to the midd ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mohs Scale Of Mineral Hardness
The Mohs scale of mineral hardness () is a qualitative ordinal scale, from 1 to 10, characterizing scratch resistance of various minerals through the ability of harder material to scratch softer material. The scale was introduced in 1812 by the German geologist and mineralogist Friedrich Mohs, in his book ''"Versuch einer Elementar-Methode zur naturhistorischen Bestimmung und Erkennung der Fossilien"''; it is one of several definitions of hardness in materials science, some of which are more quantitative. The method of comparing hardness by observing which minerals can scratch others is of great antiquity, having been mentioned by Theophrastus in his treatise ''On Stones'', , followed by Pliny the Elder in his ''Naturalis Historia'', . The Mohs scale is useful for identification of minerals in the field, but is not an accurate predictor of how well materials endure in an industrial setting – ''toughness''. Minerals The Mohs scale of mineral hardness is based on the ability ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hardness
In materials science, hardness (antonym: softness) is a measure of the resistance to localized plastic deformation induced by either mechanical indentation or abrasion. In general, different materials differ in their hardness; for example hard metals such as titanium and beryllium are harder than soft metals such as sodium and metallic tin, or wood and common plastics. Macroscopic hardness is generally characterized by strong intermolecular bonds, but the behavior of solid materials under force is complex; therefore, hardness can be measured in different ways, such as scratch hardness, indentation hardness, and rebound hardness. Hardness is dependent on ductility, elastic stiffness, plasticity, strain, strength, toughness, viscoelasticity, and viscosity. Common examples of hard matter are ceramics, concrete, certain metals, and superhard materials, which can be contrasted with soft matter. Measuring hardness There are three main types of hardness measurements: ''scratch' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corundum
Corundum is a crystalline form of aluminium oxide () typically containing traces of iron, titanium, vanadium and chromium. It is a rock-forming mineral. It is a naturally transparent material, but can have different colors depending on the presence of transition metal impurities in its crystalline structure. Corundum has two primary gem varieties: ruby and sapphire. Rubies are red due to the presence of chromium, and sapphires exhibit a range of colors depending on what transition metal is present. A rare type of sapphire, padparadscha sapphire, is pink-orange. The name "corundum" is derived from the Tamil- Dravidian word ''kurundam'' (ruby-sapphire) (appearing in Sanskrit as ''kuruvinda''). Because of corundum's hardness (pure corundum is defined to have 9.0 on the Mohs scale), it can scratch almost all other minerals. It is commonly used as an abrasive on sandpaper and on large tools used in machining metals, plastics, and wood. Emery, a variety of corundum with no value a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sunrise Ruby
The Sunrise Ruby is the world's most expensive ruby, most expensive coloured gemstone, and most expensive gemstone other than a diamond. Originally mined in Myanmar, its current name is derived from a poem of the same name, written by the 13th-century Sufism, Sufi poet Rumi. Description It is a Burmese "pigeon blood" ruby, mounted by Cartier (jeweler), Cartier and set between heptagonal diamonds weighing and . It is considered among the rarest of all gemstones. The Swiss Gemmological Institute has described it as "a unique treasure of nature" and praised its "well-proportioned cut, highly attractive colour and fine purity". The Gubelin Gem Lab in Zürich stated that "such a combination of characteristics is very rare in Burmese rubies of this size." The global chairman of Sotheby's International Jewellery Division, David Bennett, when interviewed on the ruby, stated "during his 40 years in the industry, he has never before seen a ruby of this calibre". In a Gubelin grading ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Dodoma Region")
