Wednesday, December 21, 2011

Friday, December 9, 2011

The 4 C S (diamond 4 CS) by GEMS HONOR

  • How to choose diamonds???
  • How much for one carat diamond???
     The two common questions for people looking for diamond as engagement ring or as investment.
First thing, you needed to know "the 4 CS” of diamonds you can read HERE.
     If you already know the 4 CS, then I am going to tell you how to choose diamonds starting from
COLOR, CLARITY, CUT, and then CARAT.
     I will tell you the tips to choose diamond base on the GIA grading system, because it is the most
commonly used for diamond report.

COLOR:

diamonds in side view 



- D, E, F – color grades of diamond are appear colorless to our eyes in both views "face up” and "side” (you can see in above photo, diamonds show different color in side view) even the experienced grader. To tell the different in these three levels, you needed to use diamond master set which usually use only in the lab.




Diamond prices from Rapaport
(Nov 25, 2011)

 -1 carat, VVS1, D color: $20,900/carat
-1 carat, VVS1, E color: $18,400/carat
-1 carat, VVS1, F color: $14,900/carat
-1 carat, VVS1, G color: $12,400/carat
- G, H, I, J – color grades are also appear colorless to our eyes but only in "face up.” In "side” view you will see tint or very very light color.In these range, if diamonds are larger size the color H, I, and J will appear tinted color to experienced graders.So, if you are serious about the colorless by "face up” view I will usually prefer the G as the minimum grade especially the larger diamonds.

From explanation above and the sample prices, the 2 diamonds with same size, same clarity grade but
one is D color($20,900) and another one is G color($12,400). The D color diamond is almost 70%
more expensive than the G color diamond. Both of them will be the same looking by face up view.

So if you want to spend less money but you can get the diamond look like the more expensive one,
I would recommend the G color. But if you want to keep the best quality diamond and you don’t mind
to pay more then I recommend the D color because it is more rare and also keeping diamonds as
investment, most people would prefer the D color diamond.

CLARITY:

FL and IF – are no inclusions and much more expensive than the other clarity grades. They are also very rare to find.

- From the clarity chart above; VVS1, VVS2, VS1, and VS2 are no eye-visible inclusions except VS2, but very rare to get VS2 as eye-visible inclusions. Even SI1 and SI2 are also often no eye-visible inclusions.

Diamond prices from Rapaport
(Nov 25, 2011)
-1 carat, D color,       IF$28,900/carat
-1 carat, D color, VVS1$20,900/carat
-1 carat, D color, VVS2: $18,400/carat
-1 carat, D color,    VS1: $14,300/carat
-1 carat, D color,     VS2: $11,900/carat
-1 carat, D color,     SI1:   $8,400/carat

Same idea as I explain in color grade, in this case the 2 diamonds with all factors are same but
clarity grade are different "1 ct, D color, VVS1 ($20,900)” is 75% more expensive than "1 ct, 
D color, VS2 ($11,900).

If you don’t mind to get diamonds with some inclusions just no eye-visible inclusions then
I would recommend VS1 or VS2 because these clarity grades are a lot lower price than
VVS1 or VVS2 as you can see from sample diamond prices above.

Actually the diamonds with SI1 are also common to be no eye-visible inclusions you can also
choose this grade for lower price.

As the D color is the best and the rarest color grade, the FL and IF are the best and the rarest
clarity grades, so these grades are better idea for somebody who want the best diamonds and
also using as investment.

CUT:
- The cut is the factor that easily effect to the beauty of diamonds. As a retail buyer you can usually know the quality of the diamond cut from the lab report. Many lab reports today will mention the cut grade as excellent, very good, good, fair, and poor.
- From picture above you can see the different of beauty in diamonds with varies cut grades. Normally I would recommend excellent or very good cut grade because the cut grade fair and poor are easily to see the less beauty in diamonds.
- If you are going to choose the good cut grade diamonds, keep in mind that one level of the grade is the range you may get high level in good cut grade diamond which is almost to be very good cut grade or if you choose the wrong one you may get the low level in good cut grade which is nearly to be the fair cut grade.
- In rapaport, you will not see the price related to the cut grades. The diamond dealers do set the higher price for better cut grades.
- If you don’t have experience in judging the cut grade and you are going to buy diamonds without the certificate, there is an easy way to find out the cut grade by filling the diamond proportions (table size%, crown angle, total depth%, etc.) in the program GIA FACETWARE in www.diamondcut.gia.edu it is free. Then you will get the cut grade from the program.

CARAT WEIGHT:


Samples of "magic sizes”:

- half carat
- three-quarter carat
- one carat
- 1.50 carats
- 2.00 carats
- 3.00 carats, etc.




CARAT: The unit of measurement for gem weight. One carat equals 1/5 of a gram (0.2 g.)
POINT: 1/100 of a carat (0.01 ct.)

Some example diamond prices from Rapaport (Nov 25, 2011)
1. D, VVS1, 0.99 ct price per carat is $13,500, total price = $13,365
2. D, VVS1, 1.00 ct price per carat is $20,900, total price = $20,900
3. D, VVS1, 1.49 cts price per carat is $20,900, total price = $31,141
4. D, VVS1, 1.50 cts price per carat is $25,900, total price = $38,850
5. D, VVS1, 1.99 cts price per carat is $25,900, total price = $51,541
6. D, VVS1, 2.00 cts price per carat is $40,000, total price = $80,000

From the sample prices above;
- the diamond no. 1 (0.99 ct) and no. 2 (1.00 ct) are almost the same size but the no. 2 is almost 55% more expensive than the no. 1
- No. 4 is about 24% more expensive than no. 3
- No. 6 is about 55% more expensive than no. 5
     Understanding how the magic sizes related to prices can help you choose the lower price diamonds with similar looking in size.


CONCLUSION:
     In each 4 Cs, theslightly different in some grades can cause big different in prices. There are many diamonds in the market look almost the same but very huge different in prices.
     Understanding the 4 Cs and the diamond prices system can help you choose the best diamond that matches your desire.

These are the two example diamonds with almost the same looking to unaided eyes:
1. Diamond 1.00 ct, D,VVS1 total price is $20,900
2. Diamond 0.99 ct, G,VS1 total price is $ 7,128
(the prices base on Rapaport 25 Nov, 2011)

     In case of you want to spend less money the no. 2 diamond is the better choice but if you want the better quality diamond I would recommend the no. 1

The questions you can ask yourself before choosing diamonds:

  • Who would you buy a diamond for?
  • How much do you have the budget for a diamond?
  • Do you want the best color grade or just colorless in face-up view to most people eyes?
  • Do you want the best clarity grade or just no eye-visible inclusions to most people eyes?
  • Do you want the excellent, very good, or good cut grade?

Besides choosing diamonds for you, knowing these information can also protect yourself from overprice or misleading words from some sale persons.

For example: The sale person says "This is the 1 carat G color diamond ring.”
- You have to be sure the 1 carat is for the only one piece of diamond or 1 carat of many diamonds in the ring (total gems weight) together.
- What is the clarity grade and cut grade for the G color diamond in the ring? Don’t forget, the other Cs can cause a big different in diamond prices.

Finally, if you have any more questions you can ask us in this blog or "contact us.” We would be honor to answer your questions.


COPYRIGHT GEMSHONOR.com 

Wednesday, December 7, 2011

DIAMOND 4 CS



CARAT


Diamonds and other gemstones are weighed in metric carats:
One carat is equal to 0.2 grams. Just as a dollar is divided into 100 pennies, a carat is divided into 100 points. For example, a 18-point diamond weighs 0.18 carats. But two diamonds of equal weight can have very different values depending on the other factors of the Four C’s: clarity, color and cut.
In the diamond industry, weight is often measured to the hundred thousandths of a carat, and rounded to a hundredth of a carat. Diamond weights greater than one carat are expressed in carats and decimals. (For instance, a 1.18 ct. stone would be described as "one point one eight carats,” or "one one eight.”)






HOW DID THE CARAT SYSTEM START?
The carat, the standard unit of weight for diamonds and other gemstones, takes its name from the carob seed. Because these small seeds had a fairly uniform weight, early gem traders used them as counterweights in their balance scales. The modern metric carat is equal to 0.2 grams. Today, a carat weigh is exactly the same in every markets of the world.



COLOR


Most diamonds found in jewelry stores run from colorless to near-colorless, with slight hints of yellow or brown.


There are many color-grading scale systems for diamonds. The most commonly use is GIA system, the scale begins with the letter D, representing colorless, and continues with increasing presence of color to the letter Z, or near-colorless. Each letter grade has a clearly defined range of color appearance. Diamonds are color-graded by comparing them to stones of known color under controlled lighting and precise viewing conditions. Some systems use 0 to 10, the 0 for colorless and the same idea as GIA, continues with increasing presence of color to 10. Some may use "Exceptional white until Tinted.” All systems are the same idea, colorless is the best color for diamond grading.
Many of these color distinctions are so subtle as to be invisible to the untrained eye. But these slight differences make a very big difference in diamond quality and price.






WHY DOES THE GIA COLOR GRADING SYSTEM START AT D?
Before GIA developed the D-Z Color Grading Scale, a variety of other systems were loosely applied. These included letters of the alphabet (A, B and C, with multiple A’s for the best stones), Arabic (0, 1, 2, 3) and Roman (I, II, III) numerals, and descriptions such as "gem blue” or "blue white.” The result of all these grading systems was inconsistency and inaccuracy. Because the creators of the GIA Color Scale wanted to start fresh, without any association with earlier systems, they chose to start with the letter D - a letter grade normally not associated with top quality.



CLARITY


Diamond clarity refers to the absence of these inclusions and blemishes.


Diamonds without clarity are rare, and rarity affects a diamond’s value. Every diamond is unique. None is absolutely perfect under 10× magnification, though some come close. Known as Flawless diamonds, these are exceptionally rare. Most jewelers have never even seen one.
The GIA Diamond Grading System, diamonds are assigned a clarity grade that ranges from flawless (FL) to diamonds with obvious inclusions (I3).


The GIA Clarity Scale contains 11 grades, with most diamonds falling into the VS (very slightly included) or SI (slightly included) categories. In determining a clarity grade, the system considers the size, nature, position, color or relief, and quantity of clarity characteristics visible under 10× magnification.


Flawless (FL) - No inclusions or blemishes are visible to a skilled grader using 10× magnification
Internally Flawless (IF) - No inclusions and only blemishes are visible to a skilled grader using 10× magnification
Very, Very Slightly Included (VVS1 and VVS2) - Inclusions are difficult for a skilled grader to see under 10× magnification
Very Slightly Included (VS1 and VS2) - Inclusions are clearly visible under 10× magnification but can be characterized as minor
Slightly Included (SI1 and SI2) - Inclusions are noticeable to a skilled grader using 10× magnification
Included (I1, I2, and I3) - Inclusions are obvious under 10× magnification and may affect transparency and brilliance


CUT


Cut is the factor that causes a diamond’s brilliance, fire and scintillation.


The traditional 58 facets in a round brilliant diamond, each precisely cut and defined, are as small as two millimeters in diameter. But without this precision, a diamond wouldn’t be nearly as beautiful.


Though extremely difficult to analyze or quantify, the cut of any diamond has three attributes: brilliance (the light reflected from a diamond), fire (the dispersion of light into the spectral colors), and scintillation (the flashes of light, or sparkle, when a diamond is moved).


An understanding of diamond cut begins with the shape of a diamond. The standard round brilliant is the shape used in most diamond jewelry. All others are known as fancy shapes. Traditional fancy shapes include the marquise, pear, oval and emerald cuts. Hearts, cushions, triangles and a variety of others are also gaining popularity in diamond jewelry.

As a value factor, though, cut refers to a diamond’s proportions, symmetry and polish. For example, look at a side view of the standard round brilliant. The major components, from top to bottom, are the crown, girdle and pavilion. A round brilliant cut diamond has 57 or 58 facets, the 58th being a tiny flat facet at the bottom of the pavilion that’s known as the culet. The large, flat facet on the top is the table. The proportions of a diamond refer to the relationships between table size, crown angle and pavilion depth. A wide range of proportion combinations are possible, and these ultimately affect the stone’s interaction with light.





Thursday, November 24, 2011

Ruby guide



Ruby/Corundum


In Sanskrit texts honor ruby with the word "ratnaraj,” meaning king of precious stones.

The term ruby is reserved for corundums of a red color, with other colors called sapphire.

Large, fine-quality rubies are extremely rare and valuable. The highest price per carat ever paid for a ruby was set on February 15, 2006, when Laurence Graff, a London jeweler, paid a record $425,000 per carat ($3.6 million) for an 8.62-ct. ruby, set in a Bulgari ring, at a Christie’s auction in St. Moritz.





COLOR


Color range............Red, pinkish Red, purplish Red, to orangy Red
Finest color,...........


Deep pure, vivid Red, without being too light or too dark.
Often describe as "pigeon blood" or "burmese color."
Pink, Purple, and
Orange sapphire:

  • Stones with dominant color Pink, Purple, or Orange are called pink, purple, or orange sapphire.
  • In some Asian countries, these stones sold as rubies.
  • It's important to keep such regional trade practice variations in mind if you work in different markets.
DURABILITY

Hardness (Mohs scale) 9

Toughness Excellent

Stability Environmental Factor Reaction


Heat Stable, except fracture- or cavity- filled stones


Light Stable, except irradiated stones fade quickly



Chemical Avoid boric acid powder




Major Other
Kenya, Madagascar, Myanmar (Burma)
Tanzania, Thailand

Afghanistan, Sri Lanka, Vietnam,

Type Purpose Stability Prevalence Detection

Heat

Most commonly improves color and/or clarity appearance Stable

Very common

(experts estimate that up to 95%)

May be detectable by a trained gemologist. Read more>

Diffusion

(high temperature with chemical element(s) from external source)



Improves color

Stable, some can be damaged if the stone is recut

Common

Detectable by a trained gemologist. Read more>

Fracture-filling

(with glass or epoxy)
Improves clarity appearance

Fair. Heat and chemicals can damage

Common Detectable by a trained gemologist. Read more>

Cavity-filling Improves clarity appearance by hiding cavities Fair. Heat and chemicals can damage

Occasional Detectable by a trained gemologist. Read more>

CARE and CLEANING

Type of Cleaning Advisability
Ultrasonic cleaning

Safe, but never for fracture- or cavity-filled stones

Steam cleaning

Safe, but never for fracture- or cavity-filled stones

Warm, soapy waterSafe




Alternatives Naturals Man made


Almandite garnet, Pyrope garnet,Synthetic ruby
Rhodolite garnet, Spinel, Tourmaline Synthetic spinel




Do you know?


  • Rubies generally look best viewed with incandescent light or daylight. Avoid fluorescent tubes, which have virtually no output in the red of the spectrum, and so cause ruby to appear grayish.

  • Ruby is the birthstone for July.

  • In the case of some rubies, extremely fine silk throughout the stone can actually enhance the value.

  • Ruby is the world‘s most expensive gem. But like all gem materials, low-quality pieces may be available for a few dollars per carat.


  • Large rubies of fine quality are far more rare than large sapphires of equal quality. Certainly, any untreated ruby of fine quality larger than two carats is a rare stone; untreated rubies of fine quality above five carats are world-class pieces.
COPYRIGHT GEMSHONOR.COM (2011) ALL RIGHTS RESERVED.

Tuesday, November 22, 2011

Pearls guide

A nacreous, organic gem formed in the body of a mollusk

What is the different between "natural pearl" and "cultured pearl"?

Natural pearlA pearl that forms without human assistance.Cultured Pearl: A pearl formed as the result of human intervention in the formation process.

  • ARAGONITEA crystallized form of calcium carbonate in the nacre.
  • BEAD NUCLEUS: A mother of pearl shell
  • CONCHIOLINThe organic "glue” in nacre that holds aragonite platelets together.
  • NACREThe natural substance produced by mollusks to make pearls

Base on the definition, 99.99% of pearls in the market today are cultured pearl !!!

The detection between natural and cultured pearl is using the x-ray or look at the drill-hole, if you can see the bead nucleus it is cultured pearl. If you cannot see the bead maybe natural or cultured? you cannot tell.

THE 4 MAJOR TYPES OF CULTURED PEARLS:

AKOYA:
  • Common color - white, cream, light yellow, light grey
  • The classic akoya (finest quality) is white color with rosé (pink) overtone and excellent luster
  • Akoya pearls are produced mainly in Japan and China
  • Typically size range from 2 mm to 10 mm, with an average size of 6 mm to 7 mm.
  • Akoya pearls are the highest percentage of spherical (round) shape, about 70% of all products

SOUTH SEA:
  • Common color - golden, silver, white, cream, light yellow, light grey
  • South Sea pearls typically have a soft, satiny luster.
  • South Sea pearls are produced principally in Australia, Indonesia, and the Philippines.
  • Australian South Sea pearls typically range from 8 mm to 18 mm, with most falling between 10 mm  and 15 mm.
  • Indonesian and Philippine South Sea pearls are typically about 2 mm smaller.

TAHITIAN:
  • Common color - black, and all of dark colors
  • Tahitian pearls are produced mainly in French Polynesian lagoons and the Cook Islands.
  • Tahitian pearls typically range from 8 mm to 14 mm, with an average size of 9.5 mm.
  • In the trade, the colors have names like:
Peacock - dark green gray to blue gray bodycolor and rosé to purple overtones
Aubergine - dark grayish purple bodycolor
Pistachio yellowish green to greenish yellow bodycolor

FRESH WATER:
  • Common color - white, cream, yellow, orange, and purple.
  • Chinese freshwater pearls typically range from 4 mm to 11 mm.
  • China produces the overwhelming majority of the world’s freshwater pearls, with small crops also produced in Japan and the US
  • By the late 1990s, the quality of Chinese fresh water pearls had been steadily improving. High-quality round and near-round with very attractive colors had appeared on the market.




COPYRIGHT GEMSHONOR.COM (2011) ALL RIGHTS RESERVED.

Sunday, November 20, 2011

Spinel guide


  SPINEL is a good candidate for the title of "History's Most Under Appreciated Gem." Some of the world's most illustrious "rubies" are actually spinels.One of these is the Black Prince's Ruby, a polished but unfaceted red spinel that weighs about 170 cts.
  In addition to its attractive colors, spinel is a hard, tough stone that's suitable for daily wear in any type of jewelry. It will always be popular with customers who like beautiful and unusual gems.
Hot Pink Spinel

Color   
:Violet, Blue, Orange, Red, Pink, and Purple
:The reds can rival fine ruby
:The best blue spinel is "cobalt blue spinel."

DurabilityHardness (Mohs scale)
8


Toughness
Good


StabilityEnvironmental FactorReaction


HeatStable


LightStable


ChemicalStable

Sources/OriginsMajorOther

Cambodia, Myanmar, Sri Lanka,
Tanzania, Thailand (usually black)
Afghanistan, Pakistan, Vietnam, Tajikistan

EnhanchmentNo commercial enhanchment

Care and CleaningType of CleaningAdvisability

Ultrasonic cleaningUsually safe

Steam cleaningUsually safe

Warm, soapy waterSafe

AlternativesNaturalsMan made

Almandite garnet, Amethyst, Malaya garnet,CZ

Pyrope garnet,Rhodolite garnetRuby,Synthetic corundum

Sapphire, Spessartite garnetTanzanite,Synthetic spinel

TourmalineSynthetic spinel triplet

Do you know?
: Spinel usually come in the same alluvial as corundum.
: Some spinels show color-change, star phenomena.
: "Balas ruby" is red spinel.



COPYRIGHT GEMSHONOR.COM (2011) ALL RIGHTS RESERVED.