I need to know where these gemstones mostly come from?

Question

Diamond

Emerald

Garnet

Jade

Pyrite

Obsidian

Ruby

Sapphire

Turquoise

Jasper

Answer 1

Now to start out with gem stones are cut and polished such that they can be bought at the stores so to make it a bit interesting for the teacher start out at a jewelry store or a catalog. Then back to where they are cut and polished then back to where they are mined. The majority of stones available today were mined long ago and are reused, reset, saved in museums, by the well to do etc. They are generally all found in mines with Africa having a great many deposits of gemstones in their mines. It is probably less expensive to dig up places in Africa to find gem stones along with this region is thought to be a place of origination for humans such that the discovery and excavation process probably began long ago and more areas that have such gemstones are known than in newer regions of the world where people have only recently begun to go. My understanding is diamonds affected by irradiation in the frozen regions of the world were found recently which are very blue from irradiation but it looses the color shortly after removal from the frozen ground.

http://pubs.usgs.gov/gip/gemstones/environment.html

Geologic Environment
Quartz with phantoms, Brazil Gemstones are not plentiful. Gemstones do not form "ore" deposits in the normal sense.

Gems, when present at all, tend to be scattered sparsely throughout a large body of rock or to have crystallized as small aggregates or fill veins and small cavities.

Even stream gravel concentrations tend to be small--a few stones in each of several bedrock cracks, potholes, or gravel lenses in a stream bed.

The average grade of the richest diamond kimberlite pipes in Africa is about 1 part diamond in 40 million parts "ore." Kimberlite, a plutonic igneous rock, ascends from a depth of at least 100 kilometers (60 miles) to form a diatreme (narrow cone-shaped rock body or "pipe"). Moreover, because much diamond is not of gem quality, the average stone in an engagement ring is the product of the removal and processing of 200 to 400 million times its volume of rock.

Gemstones occur in most major geologic environments.
Each environment tends to have a characteristic suite of gem materials, but many kinds of gems occur in more than one environment. Most gemstones are found in igneous rocks and alluvial gravels, but sedimentary and metamorphic rocks may also contain gem materials.

Examples of geologic environments in which gemstones are found:

Pegmatite--a coarse-grained intrusive igneous rock body, occurring as dikes (a tabular-shaped body), lenses, or veins in the surrounding rock.

Stream gravels (placers)--deposits of heavier and more durable than average minerals that have been eroded out of the original rock. Often tourmaline, beryl, and many other gem-quality minerals have eroded out of the original rock in which they formed and have moved and been concentrated locally by water in streams. Sapphires in Judith Basin County, Montana, were first found when the gravels were worked for gold from 1895 to 1930.

Metamorphic rocks--rocks that have been altered by great heat, pressure, or both. Garnet, for example, is commonly found as crystals in gneiss and mica schist.


In general all of these are created by high pressures underground over many many years. Diamond is created from carboniferous deposits that slowly change from extreme pressure from possibly something like a petroleum deposit to graphite then to shale then to diamond. The addition of other minerals turns a diamond into other things let me go look it all up as it was not my area of specialty for study in science.
Today they are being made artificially in labs predominantly diamonds as they can be used for industrial and computer purposes. They make these really cool square chip like diamonds in one lab very pretty and really cool looking.
Pyrite is ferrous - iron oxide if I remember correctly it is what was known as fools gold as it looks gold in color but it iron found in the ground in mines. Wherever there is a heavy deposit of certain minerals it can be found. I would not be surprised if they find diamonds one day in the middle east in some regions near the mountains as they have in the Rain Forest Mountains such that Indians have been murdered for their lands in those regions. If you just list stuff off it will bore the teacher as he or she has probably read it many many times.
http://www.tradeshop.com/gems/classify.html
A gemstone may be a pure chemical element (diamond is essentially pure carbon), a relatively simple chemical compound (quartz is silicon dioxide, SiO2), or a more complex mixture of various compounds and elements (the garnet family includes a highly variable mix of iron, magnesium, aluminum, and calcium silicates). The great majority of familiar gem materials are oxides or silicates (i.e., they contain oxygen and perhaps silicon) and formed as crystals during the cooling of the earth's crust over past millenia.
Gemstones may be formed in single or multiple discrete crystals (such as diamond), in massive collections of microscopic crystals (cryptocrystalline ) (such as chalcedony), or in amorphous (non-crystalline) masses (such as opal). In general, larger crystals were formed in areas of slow cooling of molten rock, and smaller crystals in areas of more rapid cooling. There are several classes of crystal structure based on symmetry of the resulting crystals, and there are also noncrystalline (amorphous) minerals used as gem materials. In addition, there are some organic materials (such as shell and bone) that have been used traditionally as gem materials....Color is the apparent result of selective absorption or transmission of different frequencies of visible light.
You will have to site all your sources I am sure an Earth Science textbook and a rock science book will give you answers to this also.

Generally the concept seems to be most are created from molten lava but diamond is thought to be made from pressure under ground.


http://www.emporia.edu/earthsci/amber/go340/students/barnett/sulfides.html
Pyrite
Physical properties:
Chemical composition: Iron Sulfide (FeS2)
Hardness: 6 to 6.5
Specific gravity: 5.02
Luster: metallic or splendent
Color/Streak: brass-yellow tarnish/greenish or brownish-black
Cleavage/Fracture: none/ conchoidal
Crystal System: isometric
Crystal Form: pyritohedron
Tenacity: brittle
Geological/Geographical occurrence: found in sedimintary rocks around or in hydrothermal veins/In the U.S., there are also many fine localities. In Park City, Bingham Co., Utah, very large, well shaped pyritohedrons and pyrite cubes have been found, as well as in the American Mine in the Bingham Canyon, Salt Lake Co., Utah. Large, intergrown cubes, many times partially octahedral, occur in abundance at Leadville, Lake Co., Colorado. Pyrite "Dollars" are mostly found in Sparta, Randolph Co., Illinois. The French Creek Mine in Chester Co., Pennsylvania is famous for the octahedral crystals that occur there, although most are distorted. Many interesting nodules were recently discovered in Alden, Monroe Co., New York

Pyrite was polished by the Native Americans in the early times and used as mirrors. Today, it is used as an ornamental stone, as well as a very popular stone for the amateur collector. It is sometimes used as gemstone by being faceted and polished for use as a side jewel in a ring, necklace, or bracelet. Pyrite is many times wrongly called "Marcasite" in the gem trade (The Mineral and Gemstone Kingdom).
This one has excellent references and history you must go read this one:

http://www.findarticles.com/p/articles/mi_m0GDX/is_2_77/ai_84017544

Africa is a special place for gemstones. It is the home of some of the oldest-known gem mines as well as the source for several new and now-well-known gem varieties. It seems as if every year new finds of important gemstones are made from every part of the continent, and, just as rapidly, these localities often stop producing. Africa is the second-largest continent, with more than 30 million square kilometers, or 20 percent of the earth's land mass. Volumes have been written on some of the localities that produce gems; this article will touch on only the most important mines. We begin in the north with Egypt and some of the oldest documented mines and continue south, where new mines are being found every year.
Diamonds are probably the best-known gemstones produced on the African continent, and because so much has been written on their discovery and subsequent mining operations, they are not included in this article. Rather the focus is on other transparent species of good quality. Although there are hundreds of localities for these transparent gems, there are literally thousands that produce cabochon materials, too many to cover in an article of this length....
EGYPT

When considering historic gem localities in Africa, many think of King Solomon's mines or the emerald mines of Cleopatra. ....
Egypt is also the home of some of the best peridot, the gem variety of forsterite....

MALI

In the last few years a yellow-green to brown mixture of two garnet species, grossular and andradile, has been coming from the Diakon Arrondissement, Mali (table 1), and is being sold as grandite, a combination of the first few letters of each species.....
NIGERIA

For years Nigeria (table 2) was known for its intense blue aquamarine, a gem variety of beryl, considered by many to be the finest commercial quality available, even with the minor inclusions inherent in the material. As supplies ran short the Nigerian miners found a new source of tourmaline (elbaite) in brownish-red to red colors, some of which is considered to be rubellite. ....

Answer 2

All of those gemstones can be found naturally, therefore they are all minerals. However zircons are commonly fabricated as a cheap knock-off to real diamonds. Colors can be altered and enhanced by unscrupulous jewelers.

Answer 3

A lot of the world's emeralds come from Colombia. Don't know about the others. I think Asia has a lot of Jade, at least they use it a lot in their jewerly.

Answer 4

Go to Wikipedia and look them up

Answer 5

from the ground.