Ruby Eduction - July's Birthstone

Birthstone: July
Moh's hardness: 9
Specific Gravity: 3.97-4.05
Color: Varying red
Chemical Composition: Al2O3 aluminum oxide
Refractive Index: 1.762-1.778

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Two color varieties of curndum are used for making jewelry, the red ruby and the sapphire. Common corundums i.e. those not of gemstone quality serve as cutting and polishing material. The well-known polishing material emery is mainly fine-grain corundum, to which magnetite, hematite and quartz are added. The name corundum has its origin in India and probably referred to ruby.

Ruby is named because of its red color. It was not until about 1800 that ruby, as well as sapphire, was recognized as belonging to the corundum species. Before that date, red spinel and the red garnet were also designated as ruby.

The red color varies within each individual deposit, so it is not possible to determine the source area from the color. The designation "Burma ruby" or Siam ruby" are therefore strictly erroneous and refer more to quality than origin. The most desirable color is the so-called "pigeons blood", pure red with a hint of blue. The distribution of color is often uneven, in stripes and spots. The substance that provides the color is chromium and in the case of brownish tones, iron is present as well. AS a rough stone ruby appears dull and greasy but when cut the luster can approach that of a diamond. Heat treatment is commonly used to improve the color.

Ruby is the hardest material after diamond. Inclusions are common. They are not always indicative of lower quality, but show the difference between natural and synthetic stones. The type of inclusion {minerals, growth structures, canals, or other cavaties} often indicates the source area.

Sapphire Education - Septembers Birthstone

Birthstone: September
Moh's hardness: 9
Specific Gravity: 3.95-4.03
Color: Blue in various tones, colorless, pink, orange, yellow, green, purple, black
Chemical Composition: Al2O3 aluminum oxide
Refractive Index: 1.762-1.788

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The name sapphire {greek means blue} used to be applied to various stones. In antiquity and as late as the Middle Ages, the name sapphire was understood to mean what is today described as lapis lazuli. Around 1800 it was recognized that sapphire and ruby are gem varieties of corundum. At first the blue variety was called sapphire and corundums of other colors {with the exception of red} were given special, misleading names, such as "oriental peridot" for the green variety or "oriental topaz" for the yellow type.

Today corundums of gemstone quality of all colors except red are called sapphire. Red varieties are called rubies. The various colors of sapphire are qualified by description, e.g. green sapphire or yellow sapphire. Colorless sapphire is called leuko-sapphire {greek means white}, pinkish orange sapphire Padparadscha.

There is no definite demarcation between ruby and sapphire. Light red, pink or violet corundums are usually called sapphires, as in this way they have individual values in comparison with other colors. If they were grouped as rubies, they would be stones of inferior quality. The coloring agents in blue sapphire are iron and titanium; and in violet stones, vanadium. A small iron content results in yellow and green tones; chromium produces pink, iron and vanadium orange tones. The most desired color is a pure cornflower-blue. In artificial incandescent light, some sapphires can appear to be ink-colored or black-blue.

Through heat treatment at temperatures of about 3100-3300 degrees F {1700-1800 degrees C}, some cloudy sapphires, non distinct in color, can change to a bright blue permanent color.

Hardness is the] same as ruby and also differs clearly in different directions {an important factor in cutting. There is no fluorescence characteristics for all sapphires. Inclusions of rutile needles result in a silky shine; oriented, i.e. aligned, needles cause a six-rayed star sapphire.

Onyx - August's Alternate Birthstone

Onyx: comes in many forms, from sardonyx, to cameo's, to intaglio's, to cabochons, and many more forms.

Birthstone: August
Moh's hardness: 7
Specific Gravity: 2.65 - 2.66
Color: Black, white, green, brown, red
Chemical Composition: SiO2 - Silicon Dioxide
Refractive Index: 1.543 - 1.552 to 1.545 - 1.554

Onyx is a layer stone with the combination of a black base and white upper layer also called true onyx or Arabic onyx. In cabochons and beads, black and white layers may alternate. On the other hand, onyx is also a name sometimes used for unicolored chalcedony. This must not be confused with onyx marble, which in short is also called onyx. The name onyx has its origin in the Greek language and means "fingernail" probably because of its weak transparency.

Onyx Intaglio: name for engraving with negative image into that stone, as used for seals.

Onyx Cameo: name for a relief which is cut so that it is raised, usually the bottom layer being a dark color while the relief being carved out of the white layer on top.

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Peridot Gemstone Education - August's Birthstone

PERIDOT also called Chrysolite and Olivine

Birthstone: August
Moh's hardness: 6.5-7
Density: 3.28-3.48
Color: Yellow-green, olive-green, brownish
Chemical Composition: (Mg,Fe)2SiO4
Refractive Index: 1.650-1.703

Peridot is the best known gem variety of olivine, a species name for a series of magnesium-iron rich silicate minerals. This bright yellow-green to green to a brownish colored gemstone has caught the fancy of humans for thousands of years. Some historians even think that at least some of the "emeralds" worn by Cleopatra were actually peridot! Much of its recent popularity can be explained by its currently being recognized as the birthstone for the month of August, people wear the stone because it is supposed to bring the wearer success, peace, and good luck.

The United States was for many years the largest producer of peridot, the value of production in 1993 was estimated to be about $1.5 million, according to the USBM. Now a days, the United States is getting major Competition from China and Pakistan for the title of world's largest producer. Arizona and New Mexico produce the largest supply of peridots in the US.

Historically important deposit was on the Red Sea volcanic island Zabargad (St. John), 188 miles east of Aswan Egypt; it was mined for 3500 years but forgotten for many centuries and rediscovered only around 1900. Most of the earliest known peridot gems came from this location and small amounts of material are still being produced from there today. Later, very large, fine-quality peridot was produced from deposits in Myanmar (formerly Burma). These deposits were well known for their 20- to 40-carat cut stones of superb color and clarity, but since the socialist government came to power, the supply of Burmese peridot has been curtailed to such a point as to no longer be a factor in the industry. One can only guess as to whether the deposits are mined out, or if government policies have resulted in the shortage of material.

Diamond Eduction - 4 C's of Diamonds

Things to know when buying Diamonds, first we'll start with the 4 C's of diamonds (clarity, cut, color, carat) and then finishing with some other diamond facts. For more information and diagrams on the 4 C's of diamonds check out our ebay store diamond page: http://stores.ebay.com/OldCities-Estate-Jewelry/Diamond-Information.html.

THE 4 C's of Diamonds!

Cut - the most important of the 4

Cut refers to the shape of the stone and also gives of the brilliance of the stone. Diamonds can come in all different shapes from round, princess, emerald, pear, etc. You can also find diamonds uncut or rough, these diamonds are older and have much value, but little brilliance or luster. To grade the cut of a diamond you look at the shape of the cut, proportions and symmetry as well as outer marks, these are all taken into consideration. The brilliance of a diamond comes from the underneath table, how many facets there are, how they are cut and how the light hits off of each of those facets, this is what makes the diamond sparkle.

Color - How colorless is the diamond?

Diamond color is hard to judge by the naked eye, most use what is called a loop. Color is graded using the alphabet staring at D (best in color or colorless) all the way down to Z (a yellow diamond). Diamonds also come in what they call fancy colors: green, red, blue, purple and yellow, while also coming in brown and black. These stones are generally graded differently.

Clarity - How clear is the diamond?

Clarity refers to the internal/external flaws or inclusions the diamond has. Clarity starts as LR which is internally flawless or inclusion free when looking through a 10 X magnification, all clarity is judged with some sort of magnifier, never done by the naked eye, the naked eye misses many inclusions. If the stone has very few or minor inclusions it is graded VVS, VS is very small inclusions, going to SI small inclusions, to I distinct inclusions and rounding out at PI very large inclusions. To get the clarity of a diamond the best way to do it would to be to go to your local jeweler and ask.

Carat - How big is the diamond?

Carat weight is determined by the width, height, depth, stone shape and stones specific gravity.

OTHER DIAMOND FACTS:

Chemical composition -- Almost pure carbon, crystallized under extremes of heat and pressure.

Color -- Colorless to yellow, brown, orange, blue, green, pink, black. Most diamonds are slightly yellowish, and in this general color range, those most approaching absolute lack of color are most prized. However, brightly colored diamonds are much rarer and more expensive.

Optics -- R.I. 2.417. Dispersion 0.044 (high).

Durability -- Hardness 10 on Mohs scale. The hardest natural substance. Diamonds can be cut and polished only with other diamonds, and only because of slight directional differences in hardness and a perfect octahedral cleavage. While diamonds are tough, they can be chipped along sharp girdles or facet edges. Diamonds are also highly heat resistant, but they can be burned if subjected to prolonged high heat.

Crystal structure -- Isometric (cubic).

Specific Gravity -- 3.515.

Sources -- The major sources include southern Africa, Australia, and Siberia. In North America, the best known source is at Murfreesboro, Arkansas, although it has not been commercially developed. Significant deposits have been found recently in Canada.

Is your Tanzanite Coated?

A recent article was released about tanzanite, we thought we would share. Rest assured that ALL tanzanite sold at OldCities.com has been tested and is 100% natural and has not been coated. We are merely sharing the article to make you aware of this new process people are using to up the value of a tanzanite.

ARTICLE POSTED MAY 27, 2008
Two gemological labs that specialize in colored-gemstone identification have identified a new, non-permanent type of tanzanite treatment that requires disclosure at the point of sale.

The American Gem Trade Association Gemological Testing Center (AGTA-GTC) and American Gemological Laboratories (AGL) recently received faceted tanzanite samples that were later determined to have been coated.

Evan Caplan of Omi Gems sent samples to several labs after a light repolishing of a few stones resulted in a noticeable loss of color.

"Until now, we had not identified a coating on tanzanite to improve its color," AGTA-GTC Director Lore Kiefert said in a release issued on Friday.

The treatment is not immediately obvious, but careful examination with a microscope and in immersion provided clear indications of the coating in most instances, said Christopher Smith, vice president and chief gemologist of AGL.

"This was evidenced by abrasions along facet junctions and at the culet where the coating had worn off, as well as a subtle iridescence when viewing the surface with reflected light," Smith said.

Advanced analytical testing pinpointed that the coating contained cobalt.

"The most reliable means to substantiate the presence of the coating is the use of X-ray fluorescence spectroscopy," Kiefert said, adding that the cobalt is readily detected through that particular analytical technique.

Although the gemstone industry has become very familiar with the practice of heating tanzanite to achieve the best violet to blue color, the color-enhancing coating on tanzanite has not been seen before.

The majority of the tanzanite sample was composed of smaller calibrated stones. Fine color tanzanite in this size range is rarely sent to a lab and therefore would ordinarily avoid detection unless closely scrutinized.

"This is just another reminder that each and every gemstone should be fully examined to determine whether or not it has been treated," Smith said. "Today, it is not uncommon to see stones that have been treated using multiple or compound techniques to achieve a particular result."

Both Kiefert and Smith emphasized that any treatment used to modify the color of a gem should be disclosed. Coatings, in particular, are not considered permanent and in the United States are required by Federal Trade Commission guidelines to be properly disclosed at the point of sale.

OldCities Jewelry & Small Product Photography

OldCities Fine Estate & Antique Jewelry is now offering product photography. We specialize in jewelry, but have a brilliant photographer who can photo whatever product you need. We are located in the Seattle area, but are willing to travel or ship items back and forth. We have been selling jewelry online now for about 10 years, please feel free and check out a few of our jewelry photography examples.

http://oldcities.com/photography-portfolio.htm

Please feel free and contact us at anytime to discuss photographing your products. Make sure and include the type of products, how many you have and the time frame in which you need them.

CONTACT CaraLee -
Website: www.oldcities.com
eMail: caralee@oldcities.com

ABOUT OLDCITIES PHOTOGRAPHY
OldCities has been selling jewelry online for over 6 years now, within that time we have developed amazing product photographs that give online customers confidence when purchasing knowing exactly what they are getting by our crisp, clear, beautiful photos. OldCities photographs are comprised of an object or multiple objects shot on a plain background, usually white or a background of your choice. There are little or no accompanying props involved in a product shot – it is simply a well-comprised and dramatically–lit photo of the object.

PRICING GUIDELINES (may very, but this is a starting point)
Photo + Photo Shopping + Logo Stamp on Photo
1-25 items $25.00 each
10-25 items $20.00 each
25-100+ items $15.00 each

Photo Only
1-25 items $20.00 each
10-25 items $15.00 each
25-100+ items $10.00 each

A one-time setup fee of $75 will be charged, this fee will cover setting up lights, logo setup, archive creation, location shooting & traveling, etc. Once this fee is paid once we will then keep all your information on file and you will only pay per item from there on out. A travel or shipping fee may be added, but that is to be discussed before hand.

SERVICES INCLUDE
- Photograph of Product
- Web optimized image @ 72dpi (if a higher dpi is wanted, we can do that too)
- DVD or CD with jpeg images along with original shots
- All Photos’ are archived at OldCities.com
- Cropping/Photo shopping images to specific Sizes
- Adding company logo to all/some Photos if wanted

TIMELINE
-This will all depend on how many items you have, if we are photo shopping them ourselves, etc. However, we will let you know an exact timeline when we know the amount of items.

PAYMENT OPTIONS
- PayPal
- All Major Credit Cards (Visa, MasterCard, Amex, Discover)
- Check/Money Order (Made out to OldCities)

COPYRIGHT
-You will own all rights to all photos we take of your items. With your permission we may ask to use one or 2 of the photos we take of your products be used in our portfolio.