Indium (#49)

Discovered by Ferdinand Reich and T Richter of Germany in 1863, indium is a soft, silver-white metal. It has a beautiful luster to it and makes a high pitched squeal when bent. Indium was named for the indigo stripe in its spectrum. However pretty it may be, indium is toxic, and it is still being researched today to find its effects.

Indium is commonly used in:

• Low melting point alloys
• Bearing alloys
• Transistors
• Thermistors
• Photoconductors
• Rectifiers

And fun fact for you- when it is plated or evaporated into glass, it forms a mirror just as good- if not better- than silver. Its only difference is that it has superior resistance to atmospheric corrosion.

Cadmium

Discovered by Fredrich Stromeyer of Germany in 1817, cadmium is a blue white metal that is so soft you could cut it easily with a knife. It's name comes from Greek kadmeia, which is actually an ancient name for calamine, zinc carbonate. It makes sense, being cadmium was first discovered as an impurity in zinc carbonate.

Cadmium is a component of bearing alloys to give them resistance to fatigue, so it is often used in alloys with low melting points. However, this is not its main purpose- most cadmium is actually used in electroplating. Other than that, it is sometimes used in solder, NiCd batteries, and to control atomic fission reactions.

But even with its many uses, cadmium is in fact only found in small quantities associated with zinc. It is often obtained as a by-product during the treatment of zinc, copper, and other such metals. Cadmium and all of its components are poisonous.

Silver

Silver- the metal that is very well known around the world. It is bought and sold, traded and hoarded- but who discovered it?

The truth is, Caveman Ooga-Booga discovered it! Just kidding... no one really knows who discovered silver, as it has been known to man since over 3000 BC. The word comes from Latin argentum which means silver. This is also how silver came to have the symbol "Ag".

Pure silver is a bright white with a metallic luster to it. It is a metal slightly harder than gold, but it is also very ductile and malleable- something that gold AND palladium are not. Pure silver DOES have the highest electrical and thermal conductivity of all metals and also has the lowest contact resistance of all metals. It is stable in pure air and water, but it tarnishes in air containing sulfur.

The alloys of silver have many commercial uses. Sterling silver (92.5% silver, with copper or other metals) is used for silverware and jewelry. Silver is also used in:

• Photography
• Dental compounds
• Solder
• Brazing
• Electrical contacts
• Batteries
• Mirrors

While silver itself is not poisonous to humans, it's salts are due to the anions in it.

Fun Fact: Silver nitrate is often used to disinfect deep wound like fishers and gashes.

Palladium

Discovered by William Wollaston of England in 1803, palladium is named after the asteroid Pallas. Why? Because the asteroid was found in 1803 in the same time frame as palladium. Pallas is also the Greek goddess of wisdom.

Palladium itself is nothing like the asteroid- it is a steel white metal that never tarnishes in air. It is a very soft metal, and so has the lowest melting point AND density of all platinum metals. Palladium CAN become a harder, stronger metal, but only through the process of cold-working. Palladium can be crushed flat into a leaf that is as thin as an astonishing 1/250,000 of an inch.

Palladium is a good alloying agent and is often used by dentists and jewelry makers- and by us, as it is also used to make surgical instruments, electrical contacts, and watches. Fun fact: white gold is actually an alloy of gold that has been decolorized by use of- you guessed it- palladium.

Ruby

If you were born in July, then Ruby is your gem! Ruby is a gem that is very common in royal insignia and is used in very expensive jewelry. Ruby is also commonly used to celebrate a couple's 15th and 40th anniversary. The ruby was named after the Latin word for red, "ruber". This is a perfect name for it. Many of the most desired rubies are considered pigeon's blood red. The more common rubies are usually pink, orange, purple, and brownish red.

spinel

Many tales of large rubies are not true. This is so because many of the gems that were thought to be rubies were spinels, a similar gem. But I'll talk about spinels some other time. Here are some gems that ARE real. Real stones of outstanding beauty and color are the "Edwardes Ruby",weight 167 ct, displayed at the British Museum of Natural History in London, the "Rosser Reeves Star Ruby", of 138.7 ct, to be seen at the Smithsonian Institution in Washington, the "De Long Star Ruby", weight 100 ct, shown in the American Museum of Natural History in New York and the "Peace Ruby", 43 ct, which was found in 1919.

Rubies are very close to diamonds on the Moh's scale of hardness. Rubies are the second hardest, rating a 9 on the scale. So where are rubies found? Well, rubies can be found in many places, but mainly Madagascar, Thailand, Myanmar, Sri Lanka and Tanzania.For a long time, India was also thought to be a large ruby deposit. In the Sanskrit language, rubies are called ratnaraj, which means king of gems. In the ancient times, a main reason for having a ruby was because they were believed to keep bad disease away. 

Rhodium

Discovered by William Wollaston of England in 1803, rhodium is the 45th element. The name is greek for "rhodon rose", as rhodium salts create a rosy colored solution. But rhodium isn't always in salt form, and unlike salt, the metal is a silvery white.

 When exposed to red heat, the metal will change in air to sesquioxide. At higher temperatures it will often revert to its elemental form. Rhodium is one of the only metals that has a higher melting point than platinum.

Plated rhodium is very hard and has a high reflectance, which makes it useful for optical instruments and jewelry. Rhodium is also used as a catalyst in certain reactions.

Aquamarine

Aquamarines are very strange and beautiful gemstones. They are usually a deep-light blue color. The rarest and most expensive aquamarines are a rich, deep blue. Aquamarine is a member of the beryl family and ranks a 7.5 on the Mohs Scale Of Hardness. Aquamarine gets it's exotic name from the Latin words for water and sea. *Almost all gemstones get their names from Latin terms.*


Aquamarines have many legends that surround them, the most famous being that it is believed to bring the wearer good fortune, happiness, intelligence, courage, and youthfulness. As for healing and medicinal purposes, it is believed to help with anxiety and in the Middle Ages was believed to bring down the effects of poisoning.

So where do aquamarines come from?
Well, many of the world's best aquamarines are found in Brazil, but aquamarines can also be mined in:

Cat's eye aquamarine
Kenya
Nigeria
Madagascar
Zambia
Tanzania
Sri Lanka
Pakistan
Afghanistan
Russia

While most aquamarines being sold in jewelry stores today are cut into faceted gems, occasionally they are cut in cabochon styled gems and give a cat's eye effect. Aquamarine is the birthstone of those born in March and with the Zodiac sign of the Scorpio.