Agate is the birthstone for September and also for the 12th and 14th wedding anniversary.  Found all over the world, Agates come in all the many beautiful colors of the rainbow, green and blue being the rarest.  Agate is a hard stone and a variety of chalcedony formed from layers of quartz which usually show varicolored bands.  Often tiny quartz crystals form within the stone to add to the beauty and uniqueness of individual stones.  
Some of the various names are; Moss Agate, Eye Agate, Plume Agate, Rose Agate.  Agates are fairly inexpensive except for the varieties with unusual banding and scenic markings, some of which have exceeded the price of a more well-known semi-precious stone.  They are found all over the world like Africa, Asia, Brazil, Egypt, Germany, India, Italy, Mexico and USA.

Amazonite is a gem variety of Feldspar.  It displays a schiller of light which is caused by inclusions.  Schiller is a lustrous reflection from planes in a mineral grain and is similar to what is more commonly known as iridescence.  The Schiller is caused by a feature of the stone's crystal structure. 
Amazonite is found in the United States, Brazil, Australia, Russia, Zimbabwe and Namibia. 
Amazonite usually is light green to blue-green, mottled and sometimes contain light striations.  

Amethyst is the official birthstone for February; also for the 4th, 6th and 17th wedding anniversaries.
Amethyst is the purple variety of quartz and the most valued member of the quartz family.  It can display a range of color from deep purple, light lilac, mauve and lavender.  Top quality Amethyst is a deep medium purple with rose-colored flashes.  Amethyst can occur as crystals and also as "drusy", which are crystalline crusts covering the host rock.  It is found around the world in  crystalline and massive forms.  Amethyst is heat treated today to keep its rich purple color.


Aventurine is a translucent to opaque variety of micro crystalline quartz.  It contains small inclusions of shiny minerals which give the stone a sparkling effect known as aventurescence.
Aventurine ranges in color from green, peach, brown, blue and a creamy green.
Aventurine is found in India, Chile, Spain, Russia, Brazil, Austria and Tanzania.

Carnelian is a form of chalcedony, a member of the quartz family, and most of the Carnelian is heat treated today to enhance the reddish brown color.  Carnelian is found in Brazil, Russia, Madagascar, Australia, South Africa and United States.

Garnet is the birthstone for January, and the gem for the 2nd and 6th wedding anniversaries.
Garnet occurs in every color except blue and most varieties are named for their color.  Rhodolite is purplish red, hessonite is the name for an orange, cinnamon, or pinkish variety.  Tsavorite is the name given to dark green grossularite.  Uvarovite and demantoid are also green varieties.  Pyrope garnets are purplish red, orange red, crimson, or dark red.  Spessartite garnets range from yellow and orange through red to reddish brown to dark black/brown.  They are found in Australia, Brazil, Myanmar (Burma), Scotland, Switzerland and Tanzania.  Garnet are formed when high temperatures and/or pressure is a factor.

Jasper is an opaque and fine grained variety of Chalcedony.  It is found in all colors including: red brown, pink, yellow, green, gray/white and shades of blue and purple.
It often contains up to 20% of foreign (organic material and mineral oxides) which give it interesting patterns, bands and colors.  Also, because of the foreign materials, jasper is rarely uniform in color, it is usually multicolored, striped and/or spotted.  Many of these patterns resemble landscapes with mountains and valleys, thus the name "picture" is part of the name of many well know jaspers.
Jasper was a favorite gem in ancient times and is referenced in Greek, Hebrew, Assyrian and Latin literature.
Found worldwide, a wide variety of names jaspers is found in the eastern areas of the United States; California, Oregon, Idaho, Utah, Wyoming and Washington.
Picture Jasper is a petrified or a silicated mud that dripped into gas pockets in molten lava.  It became superheated and then solidified forming the unusual banded patterns which are typical of this stone.
Poppy Jasper is a famous, but increasingly rare orbicular jasper with red and yellow dots of "poppy flowers".  It is a brecciated jasper, meaning it probably came from sun-dried and oxidized iron-rich clay.  The cracks were filled in by other substances.

Lapis Lazuli is listed as the traditional birthstone for December.  Lapis is considered a rock, not a mineral.  It combines various minerals, mostly lazurite, but also contains calcite (white), sodalite (blue) and pyrite (fool's gold, a metallic yellow) and to be considered a mineral it would have only one component.
Top quality lapis lazuli comes from Afghanistan where it has been mined for more than 6000 years, but is also found in Siberia, Chile, the U.S. Pakistan and Canada.
A strong blue, sometimes with a hint of violet, lapis lazuli's value decreases with the presence of white patches (calcite), while small veins of pyrite are often prized.  A soft stone, lapis lazuli is one of the most valuable semi opaque stones.

Malachite is a popular stone which has light and dark green banded areas.  Many beautiful specimens of malachite contain special combinations with other minerals, such as azurite, cuprite or chrysocolla.
Malachite can be found in Zaire, USSR, Germany, France, Chile, Australia, Arizona and New Mexico.

Pearl is the birthstone for the month of June and given on the 3rd, 12th and 30th anniversaries.  Freshwater pearls are given on the 1st wedding anniversary.
An organic gem, pearls are formed inside mollusks such as oysters and mussels.  They are formed when a tiny stone or bit of sand gets inside the mollusc's shell.  A lustrous substance, called nacre, is secreted around the object to protect the soft internal surface of the mollusk.  Layer upon layer of nacre coats the tiny sand, thus forming a pearl.  This process takes seven to eight years.
The most valuable pearls are perfectly symmetrical, relatively large, naturally produced and have a shimmering iridescence which is called orient luster.  The principal oyster beds lay in the Persian Gulf, the coasts of India, Sri Lanka and in the Red Sea.  Chinese pearls come mainly from freshwater rivers and ponds, Japanese pearls are found in salt water.
There are many types of pearls:
Natural pearls(made without human interference),
Cultured pearls (made when a foreign substance is intentionally inserted into a living oyster.  First used in 1893);
Baroque pearls (pearls that have irregular shapes);
Biwa pearls (an irregular shaped pearl which forms in the freshwater of Lake Biwa, Japan);
Blister pearls (pearls which grow attached to the inside of the shell);
Black pearls (gray to black pearls);
Freshwater pearls (pearls which form in fresh water mollusks and resemble puffed rice);
Mabe pearls (cultivated blister pearls);
seed pearls ( small, tiny pearls used in jewelry).
Pearls vary in color from white to those with a hint of color, often pink, to brown or black.  Coloration depends on the type of mollusk and the water where the mollusk lived.  Because the nacre is organic, pearls are very sensitive to extreme heat, acids, dryness, and humidity.  Store them with care.

Peruvian blue opal is relatively rare and is only found in the Andes mountains in Peru.  It is a very translucent stone with color similar to the Caribbean Sea.  Depending on how the stone is cut it can be clear, scenic (showing varying degrees of color) or dendritic which has black fern like inclusions.  Dyed stones are quite common and sell very cheaply at gem shows and on internet auctions.

Tiger's Eye is a member of the quartz group of chalcedonies.  It is one of the chatoyant gemstones.  Chatoyancy exhibits a changeable silky luster as light is reflected within the thin parallel fibrous bands.  This effect is due to the fibrous structure of the material.
Tiger iron is composed of tiger's eye, red jasper and black hematite.  The rippled wavy bands of color often resemble a scenic view.  Marra Mamba is a form if tiger iron found in one area of Australia.  It is a very rare type of tiger iron that contains shades of red, green, yellow and blue.
Tiger's eye is mined in Western Australia, South Africa, USA, Canada, India, Namibia and Burma.

Tourmaline is the birthstone for October and for the 8th wedding anniversary.
The name Tourmaline means the stone of mixed colors.  It is available in a wide variety of colors from black to bluish-black, dark brown, yellow, medium brown, blue to neon blue, lime to dark forest green, red and reddish purple, yellow, pink and colorless.
Bi-colored and multicolored tourmalines may be green at one end and pink at the other, watermelon tourmalines are green on the outside and pink on the inside.
Tourmalines are mined everywhere in the world.

Turquoise is one of the official birth stones for the month of December.  The name turquoise is apparently related to the fact that is was brought to Europe from the Eastern Mediterranean by the Turks.  The color is, of course, turquoise, but its range of color varies from green and greenish blue to sky blue shades.
For centuries, the most valuable turquoise came from Iran (Persia) but today some specimens mined in the southwestern United States compete with it.  The name "Persian Turquoise" is now generally used to refer to any turquoise stone that does not have the black or brown veining commonly found in turquoise mined in the U.S.
Turquoise is also found in New Mexico, Arizona, California and Nevada.