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Latest News from Gemstone Industry

Carnelian, a type of a chalcedony.

Looking for deep industry perspective on Carnelian, a type of a chalcedony, a semi precious stone? Well, here's an amazing article for you talking about all you need to know about Carnelian gemstone.

 

Carnelian

Carnelian was one of the most sought after gems of antiquity. The Egyptians, Sumerians, Hittites, Babylonians, and Mycenaeans adored this gemstone. The Roman historian pliny said that “among the ancients there was no precious stone in more common use.” A majority of classical Greek and Roman seal stones were carved in carnelian or in sard, which is another name for the brownish-orange darker-toned material. Sardonyx refers to chalcedony with alternating bands or reinforcements of white and orange that was favored for the making of beads.

The ancients differentiated between five types of sardion. Of first importance was the translucent male “blood red” stone; second came the paler yellowish orange, which was considered female. Third was the darker-toned brownish orange that we call sard. The fourth classification included agate with alternating layers or stripes of brownish orange and white, and fifth was blood-red stripes alternating with white. The first three types were found in all the best tombs.

Hue, saturation, tone

Regarding the components of color hue, saturation, and tone the modern value system almost mirrors the ancient. The dark red hue is still the most desired, although it is difficult to find a true blood red. Almost all carnelians will show some evidence of an orange secondary hue. Most of the fine carnelian beads unearthed from the royal tombs at Ur are actually a medium to dark orange to reddish orange. Thus, the finest quality might be described as a medium to dark tone (seventy to eighty percent) red primary hue (eighty to ninety percent) with an orange secondary hue (ten to twenty percent). Carnelian can also occur in a medium-toned (fifty-five to sixty-five percent) highly saturated visually pure orange hue. Highly saturated stones of this hue are at least as desirable as the so-called blood reds.

Crystal

As with all chalcedony, diaphaneity plays a defining role in the quality equation. An orange stone with good crystal is more desirable than a red stone that is opaque. Crystal is the first C of connoisseurship in the evaluation of carnelian. Recently some medium-toned (sixty percent) highly translucent orange carnelian has come on the market. This material, reportedly from southern Africa, has been nicknamed “citrus agate” due to its pure orange primary hue and its high degree of translucency. Stones of this description will command the highest prices, despite the fact they are not red or even reddish.

Treatments

Most of the carnelian currently on the market has been heat treated. Since ancient times, chalcedony has been subjected to heat treatment in order to create carnelian. Under magnification, natural color carnelian will usually show evidence of the thin bands called fortification, even in stones that seem uniformly colored to the naked eye; heat treatment will burn out the bands. Acid treatment produces a dark, dense, “burnt” look in carnelian. Treated stones are less translucent than natural gems.

Most of the gems currently available are heat treated or enhanced in some fashion. Much of the material available at low cost, in calibrated sizes, is undoubtedly treated. Calibrated stones are cut to precise proportions, e.g., round stones are precisely 5mm,6mm; ovals, cushions, emerald cuts, and pear shapes will be exactly 7x5, 8x6mm, etc. The aficionado should always be suspicious of calibrated stones.

The rarity factor

The real challenge may be in finding natural stones. The same problem is encountered with turquoise. Fine natural carnelian is available; however, it’s much easier to treat low-grade material than to bother with the natural. This reflects one of the ruling dynamics of the mass market: that which can be reduced to a commodity will be reduced to a commodity. Natural gemstones are inconvenient because they don’t occur in precisely uniform color, shapes, and sizes. This unfortunate tendency can only be accelerated by the coming of the computer age.

Distortions in the market can work for the connoisseur. Noncalibrated stones, those without precise measurements in millimeters, may be available at reduced prices. Natural carnelian can often be bought at a better price in carvings. If the collector is attentive, a gem of exceptional quality often can be picked from mixed lots of uncalibrated gems at a lower price than those found in calibrated parcels.

Original articles written by Navneet Gems and Minerals, a supplier of Carnelian and other Chalcedony Gemstones.

Posted on Tuesday, November 15, 2011 - 12:46

Clarity, Color Fading, and the rarity factor in Chrysoprase

This page talks about the Clarity, Color Fading, and the rarity factor in Chrysoprase, a type of Chalcedony, a semi precious stone.

 

Clarity

Ironstone is the normal inclusion found in chrysoprase. However, with the relative abundance of material, chrysoprase is normally cut flawless. Stones from Western Australia will sometime show small black dendritic inclusions. Any visible inclusions disqualify the stone from being considered top quality.

Color fading

Chrysoprase, like gem chrysocolla, has a reputation for drying out and fading when exposed to heat or a dry environment. This is certainly true for material from older European sources, chiefly Silesia. This seems not to be the case with material found in Australia; gems from New Marlborough and Yerilla are stable. However, it is still advisable to keep chrysoprase away from long-term exposure to direct sunlight and other forms of extreme heat.

 The rarity factor

Since the start of the new millennium, high quality chrysoprase has been available in quantity and at very low prices. I learned long ago that abundance in gemstone is will-o’-the-wisp  here today, gone tomorrow! Whenever a large deposit of any gemstone is found, the material floods the market, temporarily reducing prices. The operative word here is temporarily! Deposits, even large ones, are quickly depleted. A successful collector is an accomplished opportunist and should not be put off by a relatively low price. A fine example of chrysoprase is well worth collecting.

Navneet Gems and Minerals is a supplier of Wholesale Chrysoprase Gemstone, a type of Chalcedony.

Posted on Tuesday, November 15, 2011 - 12:33

Crystal in Chrysoprase

This page talks about the Crystal in Chrysoprase, or basically the 'shine'

Crystal

 Given a consistent hue, saturation, and tone, the relative degree of translucency defines the quality grades in chrysoprase the more translucent the material the higher the price. In fact it can be said that crystal is really the first C of connoisseurship in grading not only chrysoprase but also the other varieties of agate discussed in this section. Translucency tends to decrease with size. The finest qualities of chrysoprase are often compared to jadeite. Chrysoprase, however never achieves the transparency of jadeite. Chrysoprase possesses a milky crystal, a characteristic of even the most translucent specimens. The finest jadeite exhibits a crisp, clean, limpid green hue.

Posted on Tuesday, November 15, 2011 - 12:28

Hue, saturation, tone of Chrysoprase

How does the Hue, Saturation, tone shape the Semi precious gem, Chrysoprase?

 

Chrysoprase is a Semi precious stone as it comes under the category Chalcedony, which itself is a Semi precious stone. The finest chrysoprase is usually described as apple green. It is sometime called imperial chrysoprase, an obvious attempt at a comparison to jadeite. It is a vivid visually pure green between sixty-five and seventy percent tone. The material from Marlborough Creek normally ranges from a visually pure green to a slightly bluish green. Gems from Yerilla may show a yellowish secondary hue. This yellowish secondary hue is considered a fault. Gemstones with even the slightest trace of a visible yellow secondary hue are far less desirable.

Gray is the normal mask or saturation modifier in the Semi precious gem, chrysoprase. The best of the Australian material shows no gray at all and can be best described as a vivid apple green. The general run of chrysoprase from these two sources is remarkably consistent in hue, saturation, and tone.

Another variety called lemon chrysoprase is found in Western Australia. It is a pale opaque lime green color and is actually not a chalcedony at all but a nickeloan magnesite.

Posted on Thursday, November 10, 2011 - 12:42

What is Chrysoprase and Chrysoprase History.

The basics of Chrysoprase, a Semi Precious Gemstone. 

 

What is Chrysoprase, The history of Chrysoprase, and Sources of Chrysoprase.

 

Chrysoprase (Semi precious stone) is a green chalcedony that owes its “apple green” color to the presence of trace amounts of pimelite, a type of nickel. Chrysoprase is very close-grained microcrystalline quartz.

 Two sources of chrysoprase were discovered recently in Australia, each producing, in substantial quantities, most of the material available in the market today. The first and most important source was a vast deposit found in 1965 at Marlborough Creek, Queensland. The second was unearthed in Western Australia in the Yerilla District in 1992. Material from Marlborough Cheek shows the purest green hue and is the finer of the two. Other sources include Brazil, and Kazakhstan in Central Asia, a legendary find, much of which later was determined to be green opal. Opal of a similar color is often associated with chrysoprase. In earlier times it was referred to as chrysopal.

Writting Original articles by Navneet Gems and Minerals, the source of Gem Chrysoprase, Chalcedony and other Semi precious and Precious gemstones.

Posted on Thursday, November 10, 2011 - 12:25

Clarity, Inclusions, Value And Availability of Gem Chrysocolla

Are you looking to know more than basics of Gem Chrysocolla? Here is a very interesting article.

 

Clarity

Malachite and drusy quartz are the usual inclusions found in gem chrysocolla. Though technically inclusions, either can add to the beauty of a cut gemstone.

Inclusions and value

Drusy, tiny colorless quartz crystals growing on the gem, are the most sought after inclusions in gem chrysocolla. Although perfection in all characteristics tends to be the way the finest gems are defined, the aficionado should be alert to pleasing compositions of gem chrysocolla juxtaposed with inclusions of drusy quartz. Malachite, since it is green, is a less desirable inclusion, though it can show a pleasing juxtaposition of color and pattern in a vivid blue gem. It is the skill and sensitivity of the cutter that makes all the difference is such cases.

The rarity factor

 Gem chrysocolla with the qualities discussed above is extremely rare. I might find one fine piece every few years. If a fine piece is on offer, the aficionado must be prepared to accept the price, or not have a second opportunity for many years.

Writting Original articles by Navneet Gems and Minerals, the source of Gem Chrysocolla, Chalcedony and other Semi precious and Precious gemstones.

Posted on Tuesday, November 8, 2011 - 11:33

Crystal and Cut in Gem Chrysocolla

Learn about the Crystal and the Cut in Gemstone Chrysocolla in this Gem article.

 

Crystal in Gem Chrysocolla

Given the consistency of hue, saturation, and tone, it is the degree of transparency that defines the various grades of gem chrysocolla. This gem is never completely transparent; it is translucent. It is the degree of translucency that is the defining factor. The greater the translucency the more the gem will be seen to glow in the light. It can be said that crystal is really the first C of connoisseurship in gem chrysocolla, as well as in the other agate varieties to be discussed in this section. Visually pure blues with a high degree of translucency is more desirable than an opaque pure blue.

Cut

Gem chrysocolla is often cut in freeform (nonsymmetrical) shapes. Shape has little effect on value except that the more interesting freeforms may command a premium. Particularly translucent gems will some-times be faceted.

Writting Original articles by Navneet Gems and Minerals, the source of Wholesale Gem Chrysocolla, and other Chalcedony Gemstones, and Semiprecious and Precious Gemstones.

Posted on Tuesday, November 8, 2011 - 11:22

Color fading factor in Chrysocolla Gemstone

Does the color in Chrysocolla fade naturally? Not naturally, but in a dry environment definitely.

 

It is estimated that over eighty percent of gem chrysocolla is subject to a degree of color fading when exposed to a dry environment. This is particularly true of the Mexican material. As the stone dries out, the translucency and the color saturation of the gem are both diminished. According to Chris Boyd, a dealer who spends summers in upstate New York and winters in Arizona, and who has worked with gem chrysocolla for many years, fading is an issue in areas with an average relative humidity below fifty-five percent. His stone looks much better in New York than in the Arizona desert. Fading can be reversed when the gem is rehydrated by directly exposing it to moisture or to a moist environment for a short period of time.

Writting Original articles by Navneet Gems and Minerals, the source of Wholesale Non-color fading and fading Chrysocolla, both.

Posted on Monday, November 7, 2011 - 13:03

Hue, Saturation, Tone of Chrysocolla

This gem article is about Hue, Saturation, and Tone of Chrysocolla.

 

Vividness of hue is the quality that assures gem chrysocolla a place among the precious gemstone. The hue varies from a slightly greenish medium dark-toned (fifty to seventy percent) turquoise blue to a similarly toned visually pure sky blue. The green secondary hue rarely exceeds ten percent. As with all blue gems, the smaller the percentage of secondary green, the more desirable the gem. Gem chrysocolla rarely shows any evidence of either a gray or brown mask. Thus, it has a consistently vivid hue. The tonal range of gem chrysocolla is also remarkably consistent.

Writting Original articles by Navneet Gems and Minerals, the source of Semi-Precious and Precious Gemstones from Bangkok, including Wholesale Chrysocolla.

Posted on Monday, November 7, 2011 - 12:24

What is Gem Chrysocolla?

What type of a gemstone is Gem Chrysocolla?

 

The rare rich sky-blue variety of chalcedony has been referred to variously as silicated chrysocolla, gem silica, agated-chrysocolla, and gem chrysocolla. The issue lies with the term chrysocolla. True chrysocolla is a soft, noncrystalline mineral that owes its vivid color, ranging from turquoise to sky blue, to the staining effect of copper oxides. Gem chrysocolla, by contrast, is a relatively hard cryptocrystalline silicate that has been stained blue by the same copper oxides.

 Given the vast difference in hardness, the aficionado should have little difficulty in separating the two materials by appearance alone. True chrysocolla is opaque, with subvitreous luster, and has a hardness of two to four on the mohs scale. Materials of this hardness normally can be scratched with a copper penny. Gem chrysocolla may be opaque to translucent and have a vitreous, or glassy, surface luster and, with a hardness of seven, it is harder than steel. Standard gemological tests can easily separate the two materials. True chrysocolla may have all the beauty of gem chrysocolla, except the luster, but it lacks the requisite hardness and durability necessary to qualify it as a gemstone.

Much of the finest gem chrysocolla is found in the copper mines of Pinel County, Arizona. In the 1960s a deposit of the gem was found on the island of Taiwan. In the East, gem chrysocolla is sometimes referred to as “blue jade,” an unfortunate term that further adds to the linguistic confusion.

Writting Original articles by Navneet Gems and Minerals, the source of Wholesale Gem Chrysocolla, and many more Chalcedony.

Posted on Monday, November 7, 2011 - 12:15