Diamonds:

Diamonds are the hardest gemstone of all minerals.  Only other diamonds can scratch each other, which is why they are good to wear every day.  However, most people do not know that diamonds are breakable. There is one weak atomic direction in the structure of the stone.  If it is hit hard on that direction, it is possible to break. So when you select a diamond, you do not want to choose one with lots of fractures inside, especially near the surface. You also do not want to choose one with chips on the surface.  The chips might cause a break if it reaches the weak atomic direction later.  Diamonds love the grease from lotions, your fingers, and so on. Simple cleaning using a tooth brush in warm soapy water will help to keep it looking brilliant.

Diamond Grading:

There are 4 value factors for diamond grading called the 4 Cs: Carat Weight/Color/Clarity/Cut.

Carat Weight:  The larger the diamond, the more rare it is. Therefore, the larger size has more value if the other 3 value factors are equal.

Color:  The letters in the D to Z scale represent a range of color. Diamonds decrease in value from D to Z as the color becomes more obvious.  After Z we refer to diamonds as Fancy Colored.  The value of these stones usually increases as the color deepens.

            D E F

G H I J

K L M

N O P Q R

S T U V W X Y Z

Colorless

Near Colorless

Faint

Very Light

Light

DEF:  Diamonds of this grade are rare.  You would not see any yellow or brown tint face-up or face-down.

GHI:  These are popular grades.  There may be a slight yellow or brown tint visible, particularly when comparing G versus I stones.  However, if you set them in yellow gold, you may not notice the differences.

J+:  You will notice a yellow or brown tint in a stone, especially if it is set in white gold.

Z+:  If a diamond has more yellow or brown color than Z grade, it is classified as a Fancy Colored Diamond

Clarity:  There are two kinds of clarity characteristics, Inclusions and Blemishes.  Stones with fewer blemishes or inclusions are more valuable.  Inclusions are enclosed within a gemstone or extended into the gemstone from its surface.  These affect all grades.  Blemishes are confined to the surface and usually only affect the top two grades.  Inclusions and blemishes can help establish a gem’s identity.  Clarity grades are as follows:

Flawless (F) and Internally Flawless (IF):  Extremely rare.  You will rarely even see one in a jewelry store.

Very Very Slightly Included (VVS1۰VVS2):  Contain minute inclusions which are very difficult to see under magnification.

Very Slightly Included (VS1۰VS2):  Contain minor inclusions which are also difficult to see under magnification.

Slightly Included (SI1۰SI2):  Contain inclusions which are noticeable to see under magnification but are very hard to see with the naked eye.  This is a popular grade

Included (I1۰I2۰I3):  Contain inclusions which are obvious under magnification and may also be visible with the naked eye. 

(I1) is a popular grade for pendant and earrings.

(I2۰I3):  They often lack transparency and durability.  Not recommended.

Cut:  The cut determines the diamond’s reflective qualities and directly influences its value.  If the stone is too deep it looks dark in the middle and can also be difficult to set in some mountings.  If the stone is too shallow it looks hazy and it is possible to get chips on the edge of the girdle (where the stone sits).

The above is the basic information for diamonds. If you need more information please contact us.

 

Pearls:

Natural pearls still exist but it’s very hard to find gem quality natural pearls.  Most of the pearls you see in jewelry stores are cultured.  There are saltwater pearls and freshwater pearls.  Saltwater pearls are usually cultured near the coast using oyster mollusks.  Very well-known saltwater pearls are Akoya, Tahitian and South Sea. Freshwater pearls are cultured in ponds, lakes or rivers using mussel mollusks.  Most of these come from China.

Akoya Pearls:

  • From the coasts of Japan and China
  • Size is between 3-11mm /average size is 6-7mm
  • Most are white, creamy or silver in color, but white pearls with pink over tones are generally desirable.
  • They have excellent luster (The way light reflects off the pearl)

 Tahitian Pearls:

  • From French Polynesia and Cook islands area
  • Size is between 7-13mm/average size is 9mm
  • Most are greenish, grayish, or bluish black, peacock, aubergine, or pistachio in color. Peacock color pearls are generally the most desirable.
  • They have very good luster

 South Sea Pearls:

  • From the coasts of Australia, Indonesia, and Philippines
  • Size is between 8-15mm/average size is 11mm
  • Most are white, silver, or golden in color
  • They have a soft luster

 Freshwater Pearls:

  • From the lakes, ponds and rivers of China, Japan and USA
  • Size varies, but the shape is generally off-round or baroque
  • Color varies
  • Quality of luster varies

 In addition to these four major categories, there are other types of pearls, such as Abalone (from New Zeeland area), Fiji (from Fiji area), and Mabe and so on.

Pearl Grades: (usually all grading is done with naked eye)

Akoya Pearl:

Hanadama:  

The highest grade.  Nearly flawless, extremly high luster with amazing reflection.  This grade has very thick and high quality nacre, and a perfectly spherical shape.  Usually Hanadama pearls come with a certification.

AAA:

Very high quality grade.  Very minor or no blemishing with at least 95% of the surface clean.  This grade has very high luster with very clean reflection and thick nacre.  Spherical shape.

AA:  

Good quality.  Minor to medium blemishing with 70-80% clean surface.  This grade has high to medium luster, thick to medium nacre.  Round to slightly off-round shape.

A:

Fair quality.  Blemishing with only 50% or less clean surface.  This grade has lower luster and thin nacre.  Non-symmetrical, off-round or slightly irregular shape.

 Madama:

Madama is a high grade pearl like Hanadama.     Madama pearls have the natural color of pearls.    Madama pearls are referred to as "natural" pearls in Japan, and you will sometimes also see that designation elsewhere.

Tahitian Pearl:

AAA: 

The highest quality.  This grade has very high luster.  Blemish free to minimally blemished.  The surface imperfections in this grade are less than 10% of its surface.  This grade is very rare.

AA: 

This grade has high-medium luster.  Lightly blemished.  The surface imperfections in this grade are less than 30% of its surface.  You may see some visible imperfections.

A: 

This grade has medium luster.  Moderately blemished.  The surface imperfections in this grade are no more than 60% of its surface.  The imperfections may be visible.

B: 

This grade has poor luster.  Heavily blemished.  The surface imperffections in this grade are more than 60% of its surface.  The imperfectijons are visible.  We do not recommend this grade.

Under the regulation of Tahitian Government, below D quality pearls are not allowed to leave Tahiti (but they can be sold in Tahiti).

The above is basic information for pearls.  If you need more information please contact us.

 

Gold:

Gold is a yellow, metallic element.  It is actually too soft to be used for jewelry in general, so it is usually alloyed with 2 – 4 other metals.  Pure gold is designated with the mark 24k.  18k gold would have 18/24 or 75% gold.  14 gold would have 14/24 or 58% gold.  Examples of other popular gold alloys are shown below.

 

Gold

Silver

Copper

Zinc

Nickel

Palladium

14k  Yellow

58.5%

4%

31.2%

6.3%

 

 

14k   White

58.5%

0.5%

27%

7%

7%

 

18k   Yellow

75%

16%

9%

 

 

 

18k   White

75%

4%

4%

 

 

17%

24k   Yellow

100%