GEMSTONES

A gemstone or gem, also called a precious or semi-precious stone, is a piece of attractive mineral, which — when cut and polished — is used to make jewelry or other adornments. However certain rocks, (such as lapis-lazuli) and organic materials (such as amber or jet) are not minerals, but are still used for jewelry, and are therefore often considered to be gemstones as well. Most gemstones are hard, but some soft minerals are used in jewelry because of their lustre or other physical properties that have aesthetic value. Rarity is another characteristic that lends value to a gemstone.

Historically gemstones were classified into precious stones and semi-precious stones. Because such a definition can change over time and vary with culture, it has always been a difficult matter to determine what constitutes precious stones.

Aside from the diamond, the ruby, sapphire, emerald, pearl (strictly speaking not a gemstone) and opal have also been considered to be precious. Up to the discoveries of bulk amethyst in Brazil in the 19th century, amethyst was considered a precious stone as well, going back to ancient Greece. Even in the last century certain stones such as aquamarine, peridot and cat’s eye have been popular and hence been regarded as precious.

Nowadays such a distinction is no longer made by the trade. Many gemstones are used in even the most expensive jewelry, depending on the brand name of the designer, fashion trends, market supply, treatments etc. Nevertheless, diamonds, rubies, sapphires and emeralds still have a reputation that exceeds those of other gemstones.

Rare or unusual gemstones, generally meant to include those gemstones which occur so infrequently in gem quality that they are scarcely known except to connoisseurs, include andalusite, axinite, cassiterite, clinohumite and bixbite.

Gems prices can fluctuate heavily (such as those of tanzanite over the years) or can be quite stable (such as those of diamonds). In general per carat prices of larger stones are higher than those of smaller stones, but popularity of certain sizes of stone can affect prices. Typically prices can range from 5USD/carat for a normal amethyst to 20,000-50,000USD for a collector’s three carat pidgeon-blood almost “perfect” ruby.

SAPPHIRE

Natural sapphire

Sapphires and rubies are formed at great depth in the earth’s mantle or the lowest part of the crust[1]. Although blue is considered the normal color for sapphires, they can be found across a full range of spectral colors as well as brown, colorless, grey and black. Those other than blue in color are considered fancy color sapphires. Some natural sapphires can be found as completely transparent, or “white.” White sapphires usually come out of the ground as light grey or brown and are then heated to make them clear. However, in very rare circumstances they will be found in a clear state.

SAPPHIRE history

According to Rebbenu Bachya, and many English Bible translations, the word Sapir in the verse Exodus 28:18 means sapphire and was the stone on the Ephod representing the tribe of Issachar. However, this is extremely disputed as though it is true that the English word sapphire derives from the Hebrew sapir (via Greek sapphiros), sapphires were actually not known before the Roman Empire (and were initially considered to be forms of jacinth, rather than deserving of a word to themselves), and prior to that time sapphiros referred to blue gems in general. It is thought by scholars that the sapphire of the Bible was actually lapis lazuli – which was frequently sent as a gift between middle-eastern nations in Biblical times (Texas Natural Science Center, 2006). There is a wide range of views among traditional sources about which tribe the stone refers to.

Blue sapphire is associated with Saturn (Wojtilla, 1973), yellow sapphire with Jupiter in Vedic astrology. It is understood that word Sapphire seems to be a corrupted form of Sanipriya(Sanskrit:- Sani = Saturn, Priya = Beloved). Buddhist monks who moved to Middle East introduced the Stone as Sani piriya and eventually become sapir and sapphire.

Sapphire is the birthstone associated with September.
The 45th wedding anniversary is known as the sapphire anniversary.

DIAMONDS ARE FOREVER

the history

In mineralogy, diamond is the allotrope of carbon where the carbon atoms are arranged in an isometric-hexoctahedral crystal lattice. Its hardness and high dispersion of light make it useful for industrial applications and jewelry. It is the hardest known natural material and the fifth-hardest[citation needed] known material after aggregated diamond nanorods, ultrahard fullerite, and rhenium diboride.

Diamonds are specifically renowned as a material with superlative physical qualities; they make excellent abrasives because they can be scratched only by other diamonds, borazon, ultrahard fullerite, rhenium diboride, or aggregated diamond nanorods, which also means they hold a polish extremely well and retain their lustre. Approximately 130 million carats (26,000 kg) are mined annually, with a total value of nearly USD $9 billion, and about 100,000 kg (220,000 lb) are synthesized annually.

The name diamond derives from the ancient Greek ἀδάμας (adamas) “invincible”, “untamed”, from ἀ- (a-), “un-” + δαμάω (damáo), “to overpower, to tame”. They have been treasured as gemstones since their use as religious icons in ancient India and usage in engraving tools also dates to early human history. Popularity of diamonds has risen since the 19th century because of increased supply, improved cutting and polishing techniques, growth in the world economy, and innovative and successful advertising campaigns. They are commonly judged by the “four Cs”: carat, clarity, color, and cut.

Roughly 49% of diamonds originate from central and southern Africa, although significant sources of the mineral have been discovered in Canada, India, Russia, Brazil, and Australia. They are mined from kimberlite and lamproite volcanic pipes, which can bring diamond crystals, originating from deep within the Earth where high pressures and temperatures enable them to form, to the surface. The mining and distribution of natural diamonds are subjects of frequent controversy such as with concerns over the sale of conflict diamonds (aka blood diamonds) by African paramilitary groups.

the characteristic

A scattering of round-brilliant cut diamonds shows off the many reflecting facets.
General
Category Native Minerals
Chemical formula C
Identification
Molecular Weight 12.01 u
Color Typically yellow, brown or gray to colorless. Less often in blue, green, black, translucent white, pink, violet, orange, purple and red.[1]
Crystal habit Octahedral
Crystal system Isometric-Hexoctahedral (Cubic)
Cleavage 111 (perfect in four directions)
Fracture Conchoidal – step like
Mohs Scale hardness 10[1]
Luster Adamantine[1]
Polish luster Adamantine[1]
Refractive index 2.4175–2.4178
Optical Properties Singly Refractive[1]
Birefringence none[1]
Dispersion .044[1]
Pleochroism none[1]
Ultraviolet fluorescence colorless to yellowish stones – inert to strong in long wave, and typically blue. Weaker in short wave.[1]
Absorption spectra In pale yellow stones a 415.5 nm line is typical. Irradiated and annealed diamonds often show a line around 594 nm when cooled to low temperatures.[1]
Streak White
Specific gravity 3.52 (+/- .01)[1]
Density 3.5-3.53 g/cm³
Diaphaneity Transparent to subtransparent to transluce

learn the 4c’s about diamonds

Owning a diamond has always meant possessing something of great beauty and lasting value. Diamonds are certainly the most precious of all nature’s creations. Their fiery brilliance captures our hearts as the eternal symbol of love. But if you’re like most people, you probably know very little about diamonds.

Diamond is the name given to the crystallized form of the element Carbon. Diamonds were formed under extreme heat and pressure at our Earth’s core. They traveled to the surface through volcanic pipelines known as kimberlite during the Earth’s formation. Due to their unique physical properties diamonds have been sought after by Kings and nobles throughout eons of time.

The value of a diamond is determined by its exact quality as defined by the 4C’s: Cut, Color, Clarity, and Carat Weight.

COLOR
The best color is no color. Diamonds allow light to be reflected and dispersed as a rainbow of color. This light dispersion, or color flash, has no effect on the technical grading of color. The absolute finest colorless stone carries a D rating, descending through each letter of the alphabet to Z, designating a diamond of light yellow, brown, or gray. This body color may be caused by the presence of trace elements, such as nitrogen, within the atomic framework of the carbon crystal. These trace elements are so minute that they are scientifically measured in parts per million (ppm). As the body color becomes more intense, the grade for color descends the scale. These gradations are so minute and precise that discerning a single grade (even by an expert) under less than ideal laboratory conditions is extremely difficult. It is always best to compare diamonds graded by either the Gemological Institute of America (GIA) or the American Gem Society (AGS) for accurate color grading. When directly comparing diamonds for color, most consumers are unable to detect a difference unless they are at least two or three color grades apart. We recommend selecting a diamond with a color grade of K or better.

CUT
The cut of a diamond refers to its proportions. Of the 4C’s, the cut is the aspect most directly influenced by man. The other three are dictated by nature.

Quite often the cut of a diamond is confused with its shape. Diamonds are cut into various shapes depending upon the original form of the uncut diamond, which is referred to as “rough.” Whatever the shape, a well-cut diamond is better able to reflect light.

A diamond’s ability to reflect light determines its display of fire and brilliance. Diamonds are usually cut with 58 facets, or separate flat surfaces. These facets follow a mathematical formula and are placed at precise angles in relation to each other. This relationship is designed to maximize the amount of light reflected through the diamond and to increase its beauty.

When a diamond is cut to proper proportions, light is reflected from one facet to another and then dispersed through the top of the stone. Within the Well Cut standards are the Diamonds.com sub categories of Ideal, Excellent, and Very Good.

This range is very strict and combines the best in brilliance and fire. Technically, the head of the class.

This range is also of great beauty yet slightly more flexible regarding percentages. Many experts prefer the appearance of this range to Ideal.

This range is balanced between precise proportions and price considerations. Viewed by many as the best overall value in beauty and price.

When the cut of a diamond is too deep, some light escapes through the opposite side of the pavilion.

When the cut of a diamond is too shallow, light escapes through the pavilion before it can be reflected.

How do I know if a Diamond is Well Cut?

A well cut diamond is the secret to a beautiful and brilliant diamond. Like beauty itself, the true meaning of “well cut” is often found in the eye of the beholder. While you may prefer a particular set of proportions, someone else might prefer slightly different proportions. Personal preference, even among experts, will always be an issue in defining the best cut.

CLARITY

Almost all diamonds contain very tiny natural birthmarks known as inclusions. To determine a diamond’s clarity, an expert views it under 10 power magnification. In addition to internal inclusions, surface irregularities are referred to as blemishes. These two categories of imperfections-inclusions (internal) and blemishes (external)-make up clarity.

The fewer the imperfections, the rarer and more valuable the diamond. Many inclusions are not discernable to the naked eye and require magnification to become apparent. A laboratory-certified clarity rating of SI2 represents the point at which inclusions are technically not apparent to the average naked eye.

Contrary to popular belief, higher clarity does not always mean more beautiful. If the inclusions are not visible to the naked eye, a higher clarity does not really improve the appearance of a diamond but rather the rarity and price. A higher clarity is more desirable and valuable, but knowing that you have selected the right clarity for the right reasons is most important. We recommend a clarity of SI2 or better.

Clarity is graded using a very precise and complex method of evaluating the size, location, and visibility of inclusions. The diagrams to the right show a top view of a round diamond. The inclusions, shown in red, are an approximate sample for each clarity rating. The plotted inclusions may not be actual size for display purposes. Remember, the inclusions depicted in red are not visible to the average naked eye until the I1-I3 clarities. Below is the technical clarity scale with a description of each term.

Also not to forget the last C is for carat..the size of the diamond

Hello world!

Welcome to WordPress.com. This is your first post. Edit or delete it and start blogging!