Gemstones

Colored Gemstones

	Amber is the fossilized resin of trees. Ambers are golden orange in color. Amber contains insects (flies, frogs, lizards), moss, lichen or pine needles that were trapped millions of years ago when the resin was still...		Aquamarine comes in the color of sky blue and dark blue. Aquamarine is often dichroic, appearing colorless or blue while it is viewed from different angles. The colour of aquamarine, however, is usually more even than that of ....
	Sapphire  All gem quality corondum that is not red is called sapphire, yet most sapphires are assosiated with colour blue. Variation in color of sapphire is due to the content of iron and titanium impurities in them.....		Emerald is a green colored gemstone. Emerald gets its glossy green color from the presence of chromium and vanadium. The name emerald comes from the Greek 'smaragdos' via the Old French 'esmeralde', and really.....
	Ruby is considered the king of the gemstones. In the fascinating world of gemstones, the ruby is the undisputed ruler. Ruby is the name given to red, gem quality corondum.		Peridot has an olive or bottle green color due to the presence of iron, and an oily luster. It has high birefringence, so the doubling of the back facets can easily be seen in large peridots when....
	Cubic Zirconia is a colourless gemstone which closely resembles diamond and oftenly mistaken as diamond. The name probably comes from the Persian word 'zargun', which means 'gold-coloured'		Garnet - By the term 'garnet', the specialist understands a group of more than ten different gemstones of similar chemical composition. It is true to say that red is the colour most often encountered...
	Amethyst - Crystalline quartz in shades of purple, lilac, or mauve is called amethyst. The amethyst is extravagance in violet. For many thousands of years, the most striking representative of the quartz family		Turquoise is one of the first gems to be mined. Turquoise has an intense color which varies from sky blue to green, depending upon the amount of iron and copper in it. Being relatively soft, having a hardness of 6.
	The name diamond is derived from the Greek word adamas which means invincible. It was given in reference to diamond’s great hardness. Diamond is the hardest mineral on Earth		The name coral however comes from the Greek 'korallion', which denotes the hard, calcareous skeleton of the coral animals, or from 'kura-halos', for 'mermaid', as the fine branches...

BIRTHSTONES

Early civilization as far back as the Assyrians (1400 BC) invested rare and beautiful gemstones with magical properties. Some minerals were thought to contain a force or possess certain values and powers. For instance, amethyst was said to prevent intoxication. Tradition associates a gem with each sign of the zodiac based on a color system. Color was thought to unleash the power attributed to the birthstone. In time, birthstones became associated with calendar months rather than the zodiac. And people began to select birthstones in colors other than the original.

Zodiac Birthstones and Astrology

Birthstone Zodiac signs are the astrological version of the monthly birthstones that symbolize the month of birth. The Birthstone Zodiac signs use the twelve zodiac signs instead of the twelve calendar months. Every sign of the zodiac is ruled by one of the planets in the Solar system and each planet rules over specific gemstones according to their color. The following chart, or list, contain details of each sign and the various gem stones that are the closest to vibrate to their particular sign. The signs of the Zodiac are used to cast horoscopes from astrological calculations which are used as a guide to personality, relationships and business affairs. The twelve Zodiac signs represent the "houses" or divisions into which the heavens are charted by the astrologer. The Zodiac signs represent the placement in the sky where the sun was during the time of birth. The twelve signs of the Zodiac are Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius and Pisces. Each sign of the Zodiac influences people who were born between certain dates. Life predictions are upon the position of the planets in the "twelve houses " at the moment of the birth. The signs of the Zodiac change on, or about, the 22nd of every month. Every sign of the zodiac is ruled by one of the planets in the Solar system and each planet rules over specific gemstones according to their color. The energies associated with each planet are affected by a classical element to which the sign belongs to either fire, earth, air, or water. The gemstones assigned to each of the Zodiac signs are believed to influence both positive and negative personality traits and characteristics. Click one of the following links to find out about the personality and characteristics of each Zodiac sign and the influence of their corresponding birthstones:

NATURAL GEMSTONES

A natural gemstone is a mineral, stone, or organic matter that can be cut and polished or otherwise treated for use as jewelry or other ornament. A precious gemstone has beauty, durability, and rarity, whereas a semiprecious gemstone has only one or two of these qualities. A gem is a gemstone that has been cut and polished.

Diamond, corundum (ruby and sapphire), beryl (emerald and aquamarine), topaz, and opal are generally classed as precious stones. All other gemstones are usually classed as semiprecious.

ORGANIC GEMSTONES

The four organic gemstone groups listed below are highly prized for their beauty and rarity. However, they are not as durable as gemstones from minerals:

Amber
(hardness: 2-2.5 Mohs)
A mixture of hydrocarbons
Specific gravity: 1.05-1.096

Hard fossil resin or sap of ancient pine trees. Usually amorphous (lacks crystalline structure). Sometimes mined, sometimes gathered on seashores.

Varies from transparent to semitransparent and generally from light yellow to dark brown, but can be orange, red, whitish, greenish-brown, blue, or violet. Can be dyed in any color.

Takes a fine polish. Used mainly in making beads or other ornaments.

Coral
(hardness: 3.5-4 Mohs)
Formed mainly of calcite (calcium carbonate) or conchiolin, a horny organic substance
Specific gravity: 2.60-2.70

Each coral polyp, a tiny marine animal that lives in enormous colonies, extracts calcium carbonate from the sea and exudes it to build a protective home around and above itself. Each generation of polyps dies in its protective home and each succeeding generation builds on top of its predecessor.

Gem coral ranges from semitranslucent to opaque and occurs in white, pink, orange, red, blue, violet, golden, and black. The black and golden corals are largely horny organic substances, not calcium carbonate.

The finest coral is used to make figurines, cameos, carvings, and beads.

Jet
(hardness: 2.5-4 Mohs)
Carbon plus various hydrocarbon compounds
Specific gravity: 1.30-1.32

This compact velvet-black coal takes a good polish and is often cut into beads, bracelets, and a wide range of decorative and useful objects.

Pearl
(hardness: 2.5-4.5 Mohs)
Formed within a mollusk, such as an oyster, that deposits a substance called nacre around an irritant that entered the organism
Specific gravity: 2.71

Pearl-bearing mollusks are found in both salt and fresh water. Salt-water pearls of gem quality are usually preferred for jewelry; they are produced almost entirely by the mollusk Pinctada. Fresh-water pearls are produced by various clams and mussels.

Natural pearls come in various shapes: round, pear, drop, egg, and others. They also come in various colors, such as white, cream, light rose, cream rose, black, gray, bronze, blue, dark blue, blue green, red, purple, yellow, and violet.

SYNTHETIC GEMSTONES

Synthetic gemstones are made in laboratories or factories, not in rocks. They have virtually the same chemical composition and crystal structure as natural gemstones, so their optical and physical properties are very similar. However, they can usually be identified by the differences in their inclusions. Many gems have been synthesized in the laboratory, but only a few are produced commercially- generally for industrial and scientific purposes.
 

Natural vs. Synthetic Gemstones
Author: Debra Hamer

What is a synthetic gemstone? A synthetic gem is created in a laboratory under controlled conditions. The gem is grown from a natural gemstone “seed”. By controlling the environment in which the gem is grown, impurities and inclusions can be avoided which occur in natural gemstones. The created stones have perfect color and clarity which is so highly desired. Most natural gemstones have imperfections due to uncontrolled growing conditions in nature. Synthetic stones will have the same chemical, physical, and optical properties of their natural counterparts without the imperfections.

A good analogy for synthetic gemstone creation is growing roses. Roses grown in a hot house where their growing environment is controlled will be closer to perfection than roses that are grown in your backyard. They're both roses, but the backyard rose will most likely be flawed or imperfect due to disease, insects, and other environmental impacts. Not so with the hot house rose because of the controlled conditions.

Don't confuse simulant gemstones with synthetic gemstones. Simulants can be made up of any substance, like glass. They are made to simulate a particular gemstone, but they do not have the same chemical, physical, and optical properties of the natural gemstone like the synthetic gemstone. Some examples of simulants are cubic zirconia, moissanite, and yttrium aluminum garnet which are diamond simulants.

The most popular gemstones that synthetics have been created for are emeralds, sapphires, rubies and alexandrites. I'm sure you have seen jewelry with synthetic stones, also known as “created” gemstones in your local retail jewelry store. They are easier to obtain and less costly than natural gemstones. Synthetics have made it more affordable for people to own nice jewelry and many prefer the flawless created stones compared to the natural stones. You can usually spot a “created” stone because it's just too perfect in color and clarity. A natural stone, especially in rubies, sapphires, and emeralds, which is perfect in color and clarity, is scarce and the cost is beyond most people's means.

Should you buy a synthetic gemstone or jewelry with created stones over the natural gemstone choices? I would recommend going with your own personal preference. If you want a piece of jewelry with a flawless, perfect gem, then go with the synthetic gemstone. Also, if cost is a deciding factor. As a collector/investor my preference would be for the natural gemstone. It's value and appreciation factor will be much greater, flawed or not.

It's interesting that there are some gemstones man has not been able to synthesize in a laboratory. One example is the garnet family of gems. They have not been able to unlock garnet's secrets to create it in a lab.

How do I know if the gemstone is natural, synthetic (created), or a simulant? If you can't tell by your own examination...ask! A reputable dealer or jeweler will be honest about the origins of the stone. If they don't know or won't say, then don't buy!

Another interesting fact about gemstones that is not common knowledge to the public is that the majority of gems on the market have been treated to create or enhance their color and clarity. There are many different treatments used today. Heat treatment is the most common and widely used. I have written another article specifically regarding gemstone treatments.

IMITATION

Imitation gems have the appearance of their natural counterparts, but their physical properties are different. They are made to deceive. Man-made materials, such as glass and synthetic spinel, have been used to imitate many different gems, but natural stones can also be modified to resemble more valuable gems. It is possible to enhance authentic gemstones by hiding cracks and flaws, or by heat-treating or irradiating to improve their color. Imitation gemstones merely imitate the color or look of a natural stone. They can be made out of anything. A cubic zirconia is an IMITATION diamond, for example. A blue piece of glass could be an imitation sapphire. A variety of blue synthetic forsterite is an excellent imitation for tanzanite, while chemically, it's composition is much closer to the yellowish green peridot. Another classic example is the "alexandrite" set in many jewelry pieces is actually a variety of vanadium colored synthetic sapphire.

OPTICAL PROPERTIES

COLOR
PLEOCHROIC GEMS
REFRACTIVE INDEX
BIREFRINGENCE
FLOUROSCENCE
ALLOCHROMATIC GEMS
IDIOGHROMATIC GEMS
PARTLY-COLOURED GEMS
INTERFERENCE
LUSTRE
 

THE PHYSICAL PROPERTIES

HARDNESS
SCALES OF HARDNESS
SPECIFIC GRAVITY
CLEAVAGE AND FRACTURE
TENACITY & TOUGHNESS
MAGNETISM & ELECTRICITY
THERMAL CONDUCTIVITY
CRYSTAL SYSTEMS
CHEMICAL PROPERTIES