This article is about the mineral or gemstone, for other uses see: Topaz (disambiguation).Topaz 4 Carat Oval Shape Topaz Gemstone Ring Enhanced with Azotic(r)Treatment Heart Cut Sky Blue Topaz Ring
The mineral topaz is a silicate of aluminium and fluorine with the chemical formula Al2SiO4(F,OH)2. It crystallizes in the orthorhombic system and its crystals are mostly prismatic terminated by pyramidal and other faces, the basal pinacoid often being present. It has an easy and perfect basal cleavage and so gemstones or other fine specimens should be handled with care to avoid developing cleavage flaws. The fracture is conchoidal to uneven. Topaz has a hardness of 8, a specific gravity of 3.4-3.6, and a vitreous lustre. Pure topaz is transparent but is usually tinted by impurities; typical topaz is wine or straw-yellow. They may also be white, gray, green, blue, or reddish-yellow and transparent or translucent. When heated, yellow topaz often becomes reddish-pink. It can also be irradiated, turning the stone a light and distinctive shade of blue. A recent trend in jewelry is the manufacture of topaz specimens that display iridescent colors, by applying a thin layer of titanium oxide via physical vapor deposition.
Topaz is found associated with the more acid rocks of the granite and rhyolite type and may be found with fluorite and cassiterite. It can be found in the Ural and Ilmen mountains, Czech Republic, Saxony, Norway, Sweden, Japan, Brazil, Mexico, and the United States.
Etymology and historical/mythical usage
The name "topaz" is derived from the Greek topazos, "to seek," which was the name of an island in the Red Sea that was difficult to find and from which a yellow stone (now believed to be a yellowish olivine) was mined in ancient times. In the Middle Ages the name topaz was used to refer to any yellow gemstone, but now the name is only properly applied to the silicate described above.
According to Rebbenu Bachya, the word "Leshem" in the verse Exodus 28:19 means "Topaz" and was the stone on the Ephod representing the tribe of Dan.
Topaz is also the birthstone of November.Example of Heat Treated Topaz-Pink Topaz Pear Cut Ring
This page about Topaz includes information from a Wikipedia article.
Additional articles about Topaz
News stories about Topaz
External links for Topaz
Videos for Topaz
Wikis about Topaz
Discussion Groups about Topaz
Blogs about Topaz
Images of Topaz
Topaz is also the birthstone of November. Conduire un véhicule lourd, Société de l'Assurance Automobile du Québec, 7e édition, 2002 ISBN 2-551-19567-5. According to Rebbenu Bachya, the word "Leshem" in the verse Exodus 28:19 means "Topaz" and was the stone on the Ephod representing the tribe of Dan. Registrations of heavy trucks in South America (2002; % breakdown by manufacturer):. In the Middle Ages the name topaz was used to refer to any yellow gemstone, but now the name is only properly applied to the silicate described above. Heavy truck leading manufacturers (alphabetically]. The name "topaz" is derived from the Greek topazos, "to seek," which was the name of an island in the Red Sea that was difficult to find and from which a yellow stone (now believed to be a yellowish olivine) was mined in ancient times. In the Eastern Europe, Škoda, Tatra and GAZ are common, since they were some of the "brands" of the Soviet controlled areas.
It can be found in the Ural and Ilmen mountains, Czech Republic, Saxony, Norway, Sweden, Japan, Brazil, Mexico, and the United States. Iveco, MAN AG, Mercedes-Benz Trucks, PACCAR (DAF Trucks, Leyland Trucks), Scania AB, and Volvo Trucks (not to be confused with Volvo Automotive, which is now part of Ford Motor Company), are the leading truck manufacturers in Western Europe. Topaz is found associated with the more acid rocks of the granite and rhyolite type and may be found with fluorite and cassiterite. But, Kenworth and Peterbilt, which had started out as heavy-duty trucks for hauling logs, forest products, and steel for shipyards on the West Coast, readily saw the need for these lighter long-distance trucks. A recent trend in jewelry is the manufacture of topaz specimens that display iridescent colors, by applying a thin layer of titanium oxide via physical vapor deposition. Drivers more concerned with safety than with fuel-economy preferred the heavier Peterbilts and Kenworths. It can also be irradiated, turning the stone a light and distinctive shade of blue. The entity, which became White-Freightliner, then just Freightliner, catered directly to western fleets that wanted a lighter-aluminium cab and frame, and traveled longer-straighter distances without stopping.
When heated, yellow topaz often becomes reddish-pink. White, built a new factory in California in the early 1960s, with long-haul trucking company Consolidated Freightways. They may also be white, gray, green, blue, or reddish-yellow and transparent or translucent. While on the West Coast, the drivers preferred Peterbilt, Kenworth, and Freightliner. Pure topaz is transparent but is usually tinted by impurities; typical topaz is wine or straw-yellow. On the East Coast, where routes where traditionally shorter, and because the trucks were made there, many drivers preferred Mack Trucks. Topaz has a hardness of 8, a specific gravity of 3.4-3.6, and a vitreous lustre. There are also regional preferences with truck drivers within the United States.
The fracture is conchoidal to uneven. Larger fleet operators and public agencies tend to prefer the lower cost Freightliners, Navistar, and Ford products. It has an easy and perfect basal cleavage and so gemstones or other fine specimens should be handled with care to avoid developing cleavage flaws. Smaller fleet operators, specialized carriers, and owner operators tend to prefer Mack or Peterbilt and Kenworth products. It crystallizes in the orthorhombic system and its crystals are mostly prismatic terminated by pyramidal and other faces, the basal pinacoid often being present. . The mineral topaz is a silicate of aluminium and fluorine with the chemical formula Al2SiO4(F,OH)2. Mercedes-Benz commercial vehicle’s, with its Freightliner, Mercedes-Benz, Setra, Sterling (the old Ford Trucks), Western Star, Mitsubishi Fuso Truck and Bus (43%; Japan), and Hyundai Trucks (50%; South Korea), sold between 200,000 and a quarter of a million units worldwide that past few years.
This article is about the mineral or gemstone, for other uses see: Topaz (disambiguation).. The worldwide market share leader is DaimlerChrysler, with its Mercedes-Benz' commercial vehicle group with around a 22% global market share. Mineral galleries. (major manufacturers ranked by 2003 sales). Mindat with location data. This works against efforts to streamline and automate the assembly line. Webmineral. Part of the reason for this is that 75% of all trucks are custom specified.
Quality among all heavy truck manufacturers in general is improving, however industry insiders will testify that the industry has a long way to go before they achieve the quality levels reached by automobile manufacturers. This may be due in part to lawsuits from drivers claiming that driving a manual transmission is damaging to their knees. The trend in Europe is that more new trucks are being bought with automatic transmissions. Automatic transmissions for heavy trucks are becoming more and more common, due to advances both in transmission and engine power.
Common North American setups include 10, 13 and 18 speeds. Bigger trucks often use manual transmissions, which must be built stronger to withstand the torque their engines make. Small trucks use the same type of transmissions as cars. The only exceptions to this are Volvo Trucks and Mack Trucks, which are available with Volvo and Mack diesel engines, respectively, and Freightliner, which is a subsidiary of DaimlerChrysler and are available with Mercedes-Benz and Detroit Diesel engines.
In the United States, highway trucks almost always use an engine built by a third party, such as CAT, Cummins, or Detroit Diesel. Huge off-highway trucks use locomotive-type engines such as a V12 Detroit Diesel two stroke engine. Most heavier trucks use four stroke turbo intercooler diesel engines, although there are alternatives. Small trucks such as SUVs or pickups, and even light medium-duty trucks in North America will use gasoline engines.
Trucks can use all sorts of engines. There are a few possible cab configurations:. Modern cabs feature air conditioning, a good sound system, and ergonomic seats (often air suspended). They can range from a simple 2 to 4 foot (0.6 to 1.2 m) bunk to a 12 foot (3.7 m) apartment-on-wheels.
A sleeper is a compartment attached to the cab where the driver can rest while not driving. The cab is an enclosed space where the driver is seated. The chassis is the main structure of the truck, and the other parts attach to it. It is usually made of steel, but can be made (whole or in part) of aluminium for a lighter weight.
A truck chassis consists of two parallel U-shaped beams held together by crossmembers. Almost all trucks share a common contruction: they are made of a chassis, a cab, axles, suspension and wheels, an engine and a drivetrain. Trucks that never use public roads, such as the biggest ever truck, the Liebherr T 282B off-road mining truck, are not constrained by weight limits. Highway-legal trucks are sometimes outfitted with off-road features such as a front driving axle and special tires for applications such as logging and construction.
In Australia many trailers are connected to make road trains. They are mostly used for long-haul purposes, often in semi-trailer configuration. Heavy trucks are the largest trucks allowed on the road. Local delivery and public service (dump trucks, garbage trucks) are normally around this size.
For the UK the cut-off is 7.5 tonnes. In the US, they are defined as weighing between 6,300 kg (13,000 lb) and 15,000 kg (33,000 lb). Medium (or medium-duty) trucks are bigger than light but smaller than heavy trucks. They are comprised of:.
Light trucks are car-sized (in the US, no more than 6,300 kg (13,000 lb)) and are used by individuals and commercial entities alike. Always check up before you go. Notice that these hours are different in other jurisdictions. Violations of these laws are subject to large fines.
Many other rules apply. Rules are in place for tractor-trailer rigs, regulating how many hours a driver may be on the clock, and how much rest time/sleep time is necessary (11hrs on/10hrs off; 60hrs/7days; or 70hrs/8days). This is one reason that UPS vehicles are called 'package cars', because that exempted them from certain tax-rates. Partly this is because they are bigger, heavier, and cause more wear and tear on roadways.
Trucks have often had to pay higher tax rates, and have been subject to extensive regulation. In the United States, it took much longer for diesel engines be accepted: gasoline engines were still in use on heavy trucks in the 1970s, while in Europe they had been completely replaced 20 years earlier. Although it had been invented in 1890, the Diesel engine was not common in trucks in Europe until the 1920s. Touring car builders such as Ford and Renault entered the heavy truck market.
The first modern semi-trailers also appeared. After World War I, several advances were made: pneumatic tires replaced full rubber, electric starters, power brakes, 6 cylinder engines, closed cabs, electric lighting. In 1904, 700 heavy trucks were built in the United States, 1000 in 1907, 6000 in 1910 and 25000 in 1914. Trucks of the era mostly used two-cylinder engines could have a carrying capacity 1500 to 2000 kg.
Others, such as Peugeot, Benz and Renault also built theirs. The first internal combustion engine truck was built in 1898 by Gottlieb Daimler. Steam-powered trucks were sold in France and the United States until the eve of World War I, and the beginning of World War II in the United Kingdom. The first semi-trailer appeared in 1881, towed by a De Dion steam tractor.
The roads of the time, built for horse and carriages, limited these vehicles to very short hauls, usually from a factory to the nearest railway station. However, steam trucks were not common until the mid-1800s. Trucks and cars have a common ancestor: the steam-powered "fardier" Nicolas-Joseph Cugnot built in 1769. .
for chilled freight, removal vans, etc). A pantech is a truck and/or van with a freight hull made of (or converted to) hard panels (i.e. A Pantech truck or van is a word derivation of "pantechnicon" commonly currently used in Australia. Vehicles transporting furniture to and from the building, known as pantechnicon vans, soon came to be known simply as pantechnicons.
The shop soon closed down and the building was turned into a furniture warehouse, but the name was kept. It was originally coined in 1830 as the name of a craft shop or bazaar, in Motcomb Street in Belgravia, London; the name is Greek for "pertaining to all the arts or crafts". Pantechnicon is a disused British word for a furniture removal van. In Australia and New Zealand a small truck with an open back is called a ute (short for "utility vehicle").
Other languages have loanwords based on these terms, such as the Malay lori. This type of truck is a motor vehicle designed to carry goods, with a cab and a tray or compartment for carrying goods. The term is most commonly used in American English and Australian English to refer to what earlier was called a motor truck, and in British English is often called a lorry, a Heavy Goods Vehicle (HGV), or a wagon (sometimes spelled waggon). They come in all sizes, from the automobile-sized pickup truck to towering off-road mining trucks or heavy highway semi-trailers.
Unlike automobiles, which usually have a unibody construction, most trucks (with the exception of the car-like minivan) are built around a strong frame called a chassis. A truck is a motor vehicle for transporting goods. Mack Trucks. Scania.
DaimlerChrysler. Nissan Diesel. Iveco (Italy, but local divisions in Asia). Isuzu.
Hino (Japan)(joint ventures with Scania and Renault). Tata Motors (India, previously called Telco). Mitsubishi (Japan). Dong Feng (China).
Nissan Diesel. Scania. Fuso. Navistar.
MAN Nutzfahrzeuge. Hino. PACCAR. Iveco.
Volvo Global Trucks. DaimlerChrysler Commecial Vehicles. "Hood" : Any conventional that is NOT an "aardvark". "Aardvark" : The aerodynamically designed conventional.
"Tiltin' Hilton" :Cab-over with a sleeper berth. Slang terms
By constrast, Aerodynamic cabs are very streamlined, with a sloped hood and other features to lower drag. They also offer poorer visibility than their aerodynamic or COE counterparts. With their very square shapes, these trucks offer a lot of wind resistance and can consume more fuel. A large car or long nose is a conventional truck with a long—6 to 8 foot (1.8 to 2.4 m) or more—hood.
Conventionals are further divided into large car and aerodynamic designs. The driver is seated behind the engine, as in most passenger cars or pickup trucks. conventional cabs are the most common in North America. To access the engine, the whole cab tilts forward, earning this design the name of tilt-cab.
They were common in the United States, but lost prominence when permitted length was extended in the early 1980s. This design is almost ubiquitous in Europe, where overall truck lengths are strictly regulated. cab over engine (COE)or flat nose, where the driver is seated on top of the front axle and the engine. Luton van body - where the load area extends over the cab.
SUVs. Minivans. Full-Size vans. Pickup trucks.