Protactinium (formerly protoactinium) is a radioactive chemical element with the symbol Pa and atomic number 91. It is a dense, silvery-gray
Silver: The least costly of the precious-metal group, silver is also very malleable, ductile, and corrosion resistant. Because it is not attacked by alkaline solutions, it is used to contain caustic soda and potash in all concentrations.
The reduction in bronze price may be due to the lower copper content in the alloy. Likewise, brass is the least expensive because it contains more zinc content. Since zinc is cheaper than copper, the price of brass is reduced.
Tungsten - Tungsten is the hardest metal in the world - four times harder than titanium. Tungsten is extremely durable. It will not bend, it is very scratch resistant, and it holds a permanent polish.
RHODIUM: TOP MOST VALUABLE METAL
Rhodium is the most valuable metal and exists within the platinum group of metals. It is used in jewelry for a final finish on white gold jewelry. It occurs in the very same ore in which gold and silver exist – only, in smaller quantities.
Gold is the metal that we'll likely fall back on when other forms of currency don't work. This means that gold will always have value in tough, as well as good, economic times.
Palladium is one of the rarest metals on earth and even more scarce than platinum – 15 times more rare to be precise. If all the platinum in the world fits in your house, then every ounce of palladium can easily squeeze inside your living room.
If translated into numbers, platinum—for all of its known deposits—is considerably more rare than gold and is the rarest metal of all. And it is, truly, a gift from the heavens.
Therefore, Cesium is the softest metal.
Rhodium. Rhodium holds the title of being the most expensive precious metal on the planet.
Diamond jewelry, diamond, the most beautiful stone
Much more expensive than gold, diamond is the undisputed star among precious stones, it is the brightest, the strongest, the purest.
Shape, Size, & Color
With palladium sheets, the color is more like a gray powder than shiny silver. However, palladium coins, rings, earrings, and bars have a soft silver-white color. The silvery-white hue of palladium makes it very attractive and popular with buyers. It's typically whiter than platinum.
White gold is usually an alloy containing about 75% gold and about 25% nickel and zinc. If stamped 18 karat, it would be 75% pure gold.
Lead is the poorest conductor of heat. It conducts heat very slowly so it acts as an insulator.
The heaviest metal is osmium, which has, bulk for bulk, nearly twice the weight of lead. The specific gravity of gold is about 19 1/4, while that of osmium is almost 22 1/2. Osmium is also the most infusible of metals, remaining unaffected by a degree of heat capable of causing platinum to run like water.
Astatine is a chemical element with the symbol At and atomic number 85. It is the rarest naturally occurring element in the Earth's crust, occurring only as the decay product of various heavier elements. All of astatine's isotopes are short-lived; the most stable is astatine-210, with a half-life of 8.1 hours.
Sodium belongs to alkali group metal(first group of the periodic table) and it can easily be cut with a knife.
24-karat gold is pure (while 100% purity is unattainable, this designation is permitted in commerce for 99.95% purity), 18-karat gold is 18 parts gold, 6 parts another metal (forming an alloy with 75% gold), 12-karat gold is 12 parts gold (12 parts another metal), and so forth.
Even though platinum is softer than gold, it is much denser (heavier) and more pure. In its pure form it is approximately 95% platinum and 5% other metals.
Platinum in the Earth's crust originates from ultra-mafic igneous rocks. It can therefore be associated with rocks like chromite and olivine. In nature, pure platinum is unknown and well formed crystals are very rare.
The average concentration of gold in Earth's crust is 'very, very low,' at 4 parts per billion. In its elemental form, gold is significantly rarer than diamonds.
Platinum – A Precious Metal of Choice
Naturally white, the rarest of precious metals and the most secure setting for diamonds and precious stones, Platinum is the perfect choice for an expression of love that will last a lifetime.
Palladium is regarded as of low toxicity, being poorly adsorbed by the body when ingested. It may cause skin, eye or respiratory tract irritation, may cause skin sensitisation. Liquid may cause burns to skin and eyes.
Gold and platinum definitely count as contenders for the number one spot. Silver may be more useful industrially, but it is somewhat less rare, so less precious. Rhodium, iridium and ruthenium are perhaps the rarest, roughly 1/5 as common as platinum.