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A widely used temperature-compensated cut of quartz is the AT-cut. Careful control of temperature and stress is essential in the operation of the QCM. AT-cut crystals are singularly rotated Y-axis cuts in which the top and bottom half of the crystal move in opposite directions (thickness shear vibration) [33] [34] during oscillation. The AT-cut ...
Along with other gold-heavy quartz pieces, the gold was first believed to be bits of damaged machinery. A number of days later, the materials were examined and found to be full of gold. The “Crown Jewel” was the largest of the pieces, weighing in at 60 lb troy (22.4 kg). [4] The finding of the gold was reported by The National Enquirer. [5]
The Turban design was used on the gold Quarter Eagle, Half Eagle, and Eagle from 1795 to 1834. [6] On the Quarter and Half Eagles, the Turban design was replaced with the regular Capped Bust design in 1808 and 1807, respectively, [ 7 ] while the Eagle, having been out of production since 1804, adopted the "Coronet" Liberty Head design in 1838.
Mexico 1861 8 reales stamp, quartered for use as 2 reales value, with San Luis Potosí cancellation [1]. Bisects and splits refer to postage stamps that have been cut in part, most commonly in half, but also other fractions, and postally used for the proportionate value of the entire stamp, such as a two cent stamp cut in half and used as a one cent stamp. [2]
The gold was brought to the surface as small particles embedded in lumps of quartz. The quartz was then crushed into a fine dust by stamping batteries in a stamp mill. A stamp battery contained a row of stamps. On the bottom of each stamp was a heavy piece of iron or steel. Each battery was driven by a cam shaft which was turned by a water ...
[1] [3] One of the latter has been broken into two pieces. [4] The gold content of the four torcs has been measured using x-ray fluorescence to be between 74–78% (roughly equivalent to 17–18 carat), with 18–22% silver, some copper, and traces of iron, mercury and tin – a mix consistent with other Iron Age gold finds in Europe. [1]
The hoard includes almost 4,600 items and metal fragments, [8] [1] totalling 5.094 kg (11.23 lb) of gold and 1.442 kg (3.18 lb) of silver, with 3,500 cloisonné garnets [6] [9] and is the largest treasure of Anglo-Saxon gold and silver objects discovered to date, eclipsing, at least in quantity, the 1.5 kg (3.3 lb) hoard found in the Sutton Hoo ship burial in 1939.
Many coins throughout history were made of gold, silver and copper. Silver: Gold: Iron: Numerous Chinese cash coins were made of iron, with the first being issued by the Han dynasty in 118 BCE. From 1942 through 1952, some of the Swedish krona coins – such as the 1, 2 and 5 öre – were made of iron. Lead: Most commonly seen in southeast ...