GEMS HONOR : A GEMS & GEMOLOGY WEBSITE

GEMSHONOR : A GEMS & GEMOLOGY WEBSITE

Diamond guide by GEMS HONOR

Pearl guide by GEMS HONOR

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

SOURCES/ORIGINS

Major	Other
Kenya, Madagascar, Myanmar (Burma) Tanzania, Thailand	Afghanistan, Sri Lanka, Vietnam,

ENHANCHMENTS

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 water	Safe

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.

Pearls guide

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

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

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

ARAGONITE: A crystallized form of calcium carbonate in the nacre.

BEAD NUCLEUS: A mother of pearl shell

CONCHIOLIN: The organic "glue” in nacre that holds aragonite platelets together.

NACRE: The 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.

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.

Color   

:Violet, Blue, Orange, Red, Pink, and Purple

:The reds can rival fine ruby

:The best blue spinel is "cobalt blue spinel."

Durability	Hardness (Mohs scale)	8
	Toughness	Good
	Stability	Environmental Factor	Reaction
		Heat	Stable
		Light	Stable
		Chemical	Stable

Sources/Origins	Major	Other
	Cambodia, Myanmar, Sri Lanka, Tanzania, Thailand (usually black)	Afghanistan, Pakistan, Vietnam, Tajikistan

Enhanchment

No commercial enhanchment

Care and Cleaning	Type of Cleaning	Advisability
	Ultrasonic cleaning	Usually safe
	Steam cleaning	Usually safe
	Warm, soapy water	Safe

Alternatives	Naturals	Man made
	Almandite garnet, Amethyst, Malaya garnet,	CZ
	Pyrope garnet,Rhodolite garnet, Ruby,	Synthetic corundum
	Sapphire, Spessartite garnet, Tanzanite,	Synthetic spinel
	Tourmaline	Synthetic 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.

Sapphire guide

Sapphire/Corundum     For centuries, SAPPHIRE has been associated with royalty and romance. Its name comes from the Greek word sappheiros, which probably referred to lapis lazuli.     Most customers think all sapphires are blue, when gem and jewelry professionals use the word "sapphire" alone, they normally mean "blue sapphire."

Color: Blue, violetish Blue, greenish Blue

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

Sources/Origins:   Major                                               Other
                              Australia, Cambodia, China,              Kashmir, Rwanda
                              Kenya, Madagascar, Myanmar,         Pakistan Nigeria,
                              Sri Lanka, Tanzania, Thailand,           USA, Vietnam

Enhanchments:
Heat
Purpose: Most commonly improves color and/or clarity appearance
Stability: Stable
Prevalence: Very common (experts estimate that up to 95%)
Detection: May be detectable by a trained gemologist. Read more>

Diffusion (high temperature with chemical element(s) from external source)
Purpose: Improves color
Stability: Stable, some can be damaged if the stone is recut
Prevalence: Common
Detection: Detectable by a trained gemologist. Read more>

Fracture filling/Cavity filling
Purpose: Improves clarity appearance
Stability: Fair. Heat and chemicals can damage
Prevalence: Occasional
Detection: 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 water..........................Safe

Alternatives:
Naturals                                           Man made
Aquamarine, Kyanite, Spinel,           CZ
Tanzanite, Topaz, Tourmaline,         Synthetic sapphire
Zircon                                              Synthetic spinel

Do you know?
: Kashmir and Burmese sapphires are usually fine quality and used as collector gems because of very rare
: Kashmir sapphire's color often describe as "cornflower blue" or "velvety blue"
: Burmese sapphire's color often describe as "royal blue"
: Sapphire, ruby, and fancy sapphire are variety of species corundum.

COPYRIGHT GEMSHONOR.COM (2011) ALL RIGHTS RESERVED.