2006-08-28T21:24:00.000-07:00

Diamonds Diamonds Diamonds

Everyone knows what is a diamond but do you know how it is actually formed?Here are some insights-

Like graphite and charcoal, which is non-crystalline, diamond is an allotrope of carbon. It is the structure of its crystal lattice and the uniform bonding of the atoms within that together produce its exceptional optical and physical properties. Its scratch hardness is beyond that of all other materials. On the Mohs scale of hardness, diamond measures 10. Measured on a sclerometer, which moves a diamond across a surface under pressure until a scratch is produced, diamond is shown to be 140 times more scratch resistant than corundum (ruby and sapphire), regarded as the next hardest gemstone. In fact, only diamond will scratch diamond.

Another important physical property different from hardness, although often confused with it, is toughness. This is the ability to resist disruption under pressure. A diamond in a vice will withstand extreme pressure and puncture the steel jaws. Indentation tests indicate that to dent a diamond requires a pressure of 8,000 kg/mm2, whereas corundum will be dented under a pressure of only 2,200 kg/mm2. However, diamond is not so resistant to shock. It can shatter under a heavy blow from hard materials.Diamond crystallizes in the isometric system with octahedra (eight faces) and rhombic dodecahedra (12 faces) shapes commonly occurring, but several other crystal types are known. Among these are cubes, variations of octahedra—including the hexoctahedron (48 faces)—twin crystals, and maccles. The latter are octahedrons where one half of the crystal lattice is rotated through 180 degrees relative to the other. In processing “cuttable” diamonds, such knowledge has practical implications; cleaving can only be done cleanly along planes parallel to octahedral faces.

Important optical properties of a polished diamond—other than its colour—are seen in its high refractive index (2.4175), high degree of clarity, colour dispersion, reflectivity, adamantine lustre, and scintillation. The total effect, known as brilliance, depends entirely on the diamond’s “life” and “fire”. The purpose of “life” is to return a maximum 83 per cent of light back to the eye, without allowing it to escape through the diamond’s back or sides. “Fire” is the display of spectrum colours caused by white light reflecting internally, before it is refracted back to the eye. When either the diamond is moved or its observer moves, “fire” describes the darting flashes of spectral colours that are visible.

Totally colourless diamonds are very scarce; most contain varying traces of yellow or brown. Yellow is caused by the presence of nitrogen within the crystal structure and brown is associated with plastic deformation. Grading diamonds for colour is done by specialists using comparison sets of defined “master stones”. The record auction price bid for a colourless diamond, graded as the top, very rare white (“D” colour) and internally flawless gem was made in 1995. The Star of the Season, a pear-shaped diamond of 100.10 carats, was sold for US$16,548,750. “Fancy” colours such as fine reds, blues, greens, and pinks command the highest prices per carat. The diamond symbolizes love, endurance, and lasting value.Natural diamonds too inferior to cut are known as “boart” and are used in industrial tools, or as “carbonado” if composed of a mass of minute crystals, which is crushed into abrasive grit. Vast quantities of man-made diamonds are also manufactured synthetically for use in modern technology and in numerous industrial applications.

More info later...

2006-08-08T09:31:00.000-07:00

Knock Nevis

Ex names: 1989 Seawise Giant, 1991 Happy Giant, 2004 Jahre Viking

The worlds largest ship ever to sail the seas.

KNOCK NEVIS, is the worlds largest ship at 458.4 meters long (over 1/4 of a mile) and 68.9 meterst wide.

The KNOCK NEVIS, a ship so huge that when fully laden she can not pass through the 32 mile wide English channel because it cannot maneuver, as traveling in a straight line is its best forte.

Also when fully laden, she sits 24.5 meters deep in the sea, a depth great enough to stop her from accessing most of the world’s major ports.

When fully laden with the capacity of 4,240,865 barrels of oil the KNOCK NEVIS has a displacement of 825,614 GLW (Gross Laden Weight) metric tons. It has an unladen weight is 564,763 tons. The holds could swallow St Pauls cathedral four times over. It has a crew of 35 to 40, which means it only needs two lifeboats. Taking 5.5 miles to stop with a turning circle of over 2 miles. When this ship docks into its port it is done so very very slowly as mistakes cannot easily be rectified when there is so much weight on the move.

The cargo of oil she normally carries is worth $122 million ! separated from the sea by just 3.5cm's of steel plate !

If the Eiffel tower was laid on its side it could easily be carried on the KNOCK NEVIS.

Sid's Odyssey