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Natural drugs to revitalize and rejuvenate your skin, circulatory system, joints, muscles, digestive organs, hair growth, mental capacities, body shape, potency, erotic satisfaction and general physiology. Help to get rid of body hair. Innovative slimming solutions. Help for acne and rosacea. Help for men's and women's issues. Products to get better sleep. Products for men and women to amplify sexual feelings, orgasmic responce and all aspects of sexual potency. Help for function problems in the genital and sexual system.

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Jewelry, watches, adorns made of precious material

Welcome to this online store where you can find quality jewelry, watches and fashion for an affordable prize. Pleace click on the banners to learn more or buy. Further down on this page there is some information about the corundum, and quarts groups of gemstones, including the stones rubys, saphires, emeralds and opals.



Good online jewellers and watch shops

Exciting fashion, apparel and jewelry - A great category in this shop is exciting and sexy women's fashion for all age groups, including dresses, clothings, swimwear, lingerie, belts and scarves. Another great cathegory is colorful jewelry of artisitic design for affordable prices, and especially adorns to wear over your clothes and thus are easily seen as a part of your porsonal artistic style




Robust ornates for active people, made of titanium, tungsten carbide, carborundum and other tough noble materials

Men's Accessories, money clips, cufflinks


Luxury Italian and European jewelry, apparel, bags, shoes and decors of high artistic value

Pre-Winter Sale at FORZIERI.COM


A great diamond shop, but also a great inventory of pieces with colored stones, engagement and wedding rings is also a speciality




Here are examples of the many watches and pieces of  jewelry art you can find.

Margaret Elizabeth - Cushion Cut Drops Navy Quartz

Margaret Elizabeth - Cushion Cut Drops Navy Quartz

Faceted, cushion cut stones make up this classic earring, available in a variety of colors.Materials: Our earrings are made from sterling silver and hand dipped in 24k gold. All of our stones are semi-precious.Size: Full length measures approximately 1 2014 Margaret Elizabeth All Rights Reserved




Citrine Quartz and Red Sapphires 18K Rose Gold Pendant Necklace

Citrine Quartz and Red Sapphires 18K Rose Gold Pendant Necklace

Citrine Quartz and Red Sapphires 18K Rose Gold Pendant Necklace is vintage inspired with a special joyful radiance that will make you positively shine day or evening. Featuring 1.60 ct center stone in a four prong setting with cluster of three sapphires atop the pendant delicately suspended on a rolo chain with lobster clasp. Signature box included. Made in Italy.




Mabel Chong - Lemon Quartz Chandelier Earrings

Mabel Chong - Lemon Quartz Chandelier Earrings

Lemon Quartz or Garnet chandelier earrings with 14k gold-filled and oxidized sterling silver. 2" in length and 1 1/2" width




Woman Agate Cameo 18K Gold Ring

Woman Agate Cameo 18K Gold Ring

18K gold agate Cornelian cameo ring by Del Gatto using age-old artisan techniques to sculpt the image on Cornelian shell featuring woman's face in profile. Made in Naples Italy. Signature box included.




Agate Stone Cameo Pendant width=

Agate Stone Cameo Pendant / Pin

The Del Gatto family selects every shell and uses a unique hand carving technique. This beautiful cameo with an 18K gold frame is part of the Agata collection which uses a particular Brasilian stone. It can be worn either as a pendant or pin. Made in Naples Italy




Mabel Chong - Cocktail Party Smokey Quartz

Mabel Chong - Cocktail Party Smokey Quartz

Smooth champagne citrine hanging from pave diamond pear with 14k gold ear wire. 12 x 13 mm Smokey Quartz stone 4 x 6mm pave diamond charm Hand crafted at Mabel Chong's San Francisco studio




Mabel Chong - Smoky Quartz Drip Drops

Mabel Chong - Smoky Quartz Drip Drops

Smoky Quartz set into sterling silver with sterling silver ear hook. Smoky Quartz: 16mm rounds. Drop: 1 1/4" Handcrafted in Mabel's San Francisco Studio.




Margaret Elizabeth - Teardrop Bangle Navy Quartz

Margaret Elizabeth - Teardrop Bangle Navy Quartz

Faceted teardrops face off in this adjustable bangle. Materials: Our bangles are made from brass and hand dipped in 24k gold. All of our stones are semi-precious. Size: This bangle can be gently adjusted to fit almost any wrist size. Diameter at the widest part measures 2 This item will ship after November 10, 2016. 2014 Margaret Elizabeth All Rights Reserved




Jarin K Jewelry - Rose Quartz Checkerboard Ring

Jarin K Jewelry - Rose Quartz Checkerboard Ring

18MM checkerboard cut rose quartz cushion ring set in sterling silver plated in 18K gold. Size 7



Ashley Schenkein Jewelry - Positano Bezel Ring

Ashley Schenkein Jewelry - Positano Bezel Ring

A cushion cut stone is bezel set in a timeless gold band. 18k Vermeil, 3/8, sizes available: 6, 7, 8. Available in Moonstone, Blue Topaz, Labradorite, Rock Quartz, Ruby, Turquoise, Chrysoprase, or Green Onyx. Please allow out of stock or additional sizes up to 3 weeks for delivery. Item: R49




Mabel Chong - Costa Rica I Earrings

Mabel Chong - Costa Rica I Earrings

Gorgeous contrasting colors make these earrings pop! Dangeling together from elegant 14kgold filltwist tube earrings. 1 1/16" long, 1/4" in width. Onepair has Purple Amethyst, Ruby, Red Garnet and Blue Kyanite. One pair has London Blue Topaz, Blue Kyanite and Sky Blue Topaz.




Mabel Chong - Long Petites In Rose

Mabel Chong - Long Petites In Rose

Gorgeous burmese rubies mixed with gold filled tiny beads with rose quartz ruby and tourmaline pear drops. Earrings measures: 1.85 inch Hand crafted in Mabel Chong's San Francisco studio




Ashley Schenkein Jewelry - Positano Bezel Ring

Ashley Schenkein Jewelry - Positano Bezel Ring

A cushion cut stone is bezel set in a timeless gold band. 18k Vermeil, 3/8, sizes available: 6, 7, 8. Available in Moonstone, Blue Topaz, Labradorite, Rock Quartz, Ruby, Turquoise, Chrysoprase, or Green Onyx. Please allow out of stock or additional sizes up to 3 weeks for delivery. Item: R49




.60ct Oval Sapphire Pendant in 14k Yellow Gold

.60ct Oval Sapphire Pendant in 14k Yellow Gold

.60ct oval sapphire pendant crafted in 14k yellow gold. Comes with an 18 inch chain.




2.90 Carat Fine Quality Sapphire And Diamond Necklace In 14K Yellow Gold

2.90 Carat Fine Quality Sapphire And Diamond Necklace In 14K Yellow Gold

Our highest quality sapphire and diamonds are set into a very fine 14 karat yellow gold mounting, creating a necklace. This sapphire and diamond necklace is the type of jewelry that gets passed down from generation to generation. The diamonds are H-I color and SI2 clarity. The sapphire is fine quality deep navy blue.




7ct Oval Sapphire and Diamond Ring

7ct Oval Sapphire and Diamond Ring

This oval-shape sapphire and diamond gemstone ring is a great accessory to have! The rough cut sapphire is a solid 7 carats and is surrounded by .01 carats of diamonds, J/K color, I3 clarity. This ring is crafted in solid sterling silver and is available in sizes 4-9.




1ct Sapphire and Diamond Halo Ring

1ct Sapphire and Diamond Halo Ring

This sapphire and halo diamond ring features a 1 carat oval shape sapphire measuring 7x5 mm. The gsapphire is surrounded by 32sparkling diamonds in J-K color, I1-I2 clarity at 0.20 carats. Total gem weight is 1.20 carats. This ring is crafted in solid 14 karat white gold and available in ring sizes 4-9.




4ct Sapphire and Diamond Ring in 14k White Gold

4ct Sapphire and Diamond Ring in 14k White Gold

A very large statement piece, 14 karat white gold, 4 carat total gem weight bezel set blue sapphire and diamond ring. Diamond content is 3/4 carat in I/J color and I1 clarity.




Mabel Chong - Rose Quartz And Chalcedony Drop Earrings

Mabel Chong - Rose Quartz And Chalcedony Drop Earrings

Bezel set Rose Quartz, 14K Gold Fill brushed bead, finished with a Chalcedony drop earrings.




Heather Hawkins - The Shining Necklace - Double Terminated Crystal Quartz Point

Heather Hawkins - The Shining Necklace - Double Terminated Crystal Quartz Point

14K Gold Filled chain with3" extender chain, and clasp and Double Terminated Crystal Quartz Point Pendant. Made in USA. Please allow up to 3-5 business days for processing.




1.50ct Sapphire and Diamond Ring in 14k Yellow Gold

1.50ct Sapphire and Diamond Ring in 14k Yellow Gold

Very High Quality 14 Karat Yellow Gold 1 Carat Sapphire and 1/2ct Oval Diamond Ring. Traditionally Styled And Extremely Well-Crafted.




1ct Sapphire and Diamond Earrings

1ct Sapphire and Diamond Earrings

Feel like a princess with these fabulous sapphire earrings! The sapphire stones are oval shaped, and surrounded by diamonds set in sterling silver. Total gem weight is 1 carat. Diamond content is .01 carats, diamond color is J-K and diamond clarity is I2-I3.




2.75ct Sapphire and Diamond Earrings in 14k White Gold

2.75ct Sapphire and Diamond Earrings in 14k White Gold

14 karat white gold, 2.75 carat total gem weight sapphire and diamond earrings. Diamond content is carat in G/H color and SI3 clarity.




2ct Pear Sapphire and Diamond Earrings in 14k Yellow Gold

2ct Pear Sapphire and Diamond Earrings in 14k Yellow Gold

2ct pear sapphire and diamond earrings crafted in 14 karat yellow gold.




1 1/4ct Leverback Oval Sapphire Earrings in 14k Yellow Gold

1 1/4ct Leverback Oval Sapphire Earrings in 14k Yellow Gold

Precisely crafted 14 karat yellow gold leverback earrings featuring deep blue oval sapphires. 1 1/4ct total weight.




9ct Sapphire and Diamond Bracelet

9ct Sapphire and Diamond Bracelet

This bracelet is a classic! This bracelet contains 9 7x5mm oval sapphire gemstones. Each stone weighs 1 carats for a total weight of 9 carats. The sapphire gemstones are accented by sparkling diamonds in J-K color, I3 clarity at 0.01 carats. Total gem weight is 9.01 carats. Bracelet is 5mm wide. This bracelet is 7 inches long and has a secure, box with tongue clasp. Bracelet is crafted in platinum-plated brass.




Drama Masks Gold Pave Ring w/Opal and Diamonds

Drama Masks Gold Pave Ring w/Opal and Diamonds

Polished 9-karat white gold (17 gr) Drama Masks ring with opal (1946 ct) in a cabochon setting. 146 diamonds (133 ct) encrust the comedy and tragedy masks flanking the stage set by the opal. Other sizes are available upon request. Part of the Fleurs Du Mal collection. Hand made in Italy.




Aventurine Quartz & Murano Glass Drop Necklace

Aventurine Quartz & Murano Glass Drop Necklace

Akuamarina's Murano glass drop pendant blends tantalizing hues with Aventurine, a quartz that gives emotional tranquility while increasing concentration and creativity. It's strung on a black cord with sterling silver lobster claw clasp. Gift box included, Made in Italy.




EDWARD FT0377 28W Gold Metal Square Sunglasses

EDWARD FT0377 28W Gold Metal Square Sunglasses

EDWARD FT0377 28W by Tom Ford feature a classically cool vibe square style aviator light metal frame with opal honey acetate accent on top bar opal honey acetate front and ear piece on temple with metal 'T' logo inserts and gradient 100% UV protection lenses with logo detail. Made in Italy.




Opale Crystal Decorated Cut Out Strapless Dress

Opale Crystal Decorated Cut Out Strapless Dress

Inspired by the swinging 60s Hafize Ozbudak's cut-out dress hugs all the right curves. With a gorgeous sheen meticulously hand sewn opal-color crystal detailing and its flattering shape and mid-thigh length you will be rocking every party in one-of-a-kind style. Handmade in Italy.




Hommes Montre Bracelet Quartz Japonais Cuir Bande Noir Orange Marque

Hommes Montre Bracelet Quartz Japonais Cuir Bande Noir Orange Marque

Marque:Oulm; Pour:Hommes; Type de mouvement:Quartz Japonais; Type:Montre Bracelet,Montre Militaire; Affichage:Analogique; Materiau de l'etui:Acier Inoxydable; Couleur de cadran:Noir; Diametre du boetier approx (CM):>=5.0; Materiel de bande:Cuir; Couleur de bande:Orange,Noir; Poids Net (kg):#(0.081); Note ::Les petits sous-cadrans sur le cadran de la montre sont pour seule decoration.; Diametre du boetier approx (CM):#(5.5); Calibre:Japon PC; Marque:Oulm




Hommes Montre Bracelet Quartz Japonais Etanche Cuir Bande Marque

Hommes Montre Bracelet Quartz Japonais Etanche Cuir Bande Marque

Pour:Hommes; Type de mouvement:Quartz Japonais; Type:Montre Bracelet,Montre Militaire; Affichage:Analogique; Caracteristique:Etanche; Materiau de l'etui:Acier Inoxydable; Profondeur d'etancheite:30m; Diamotre du botier approx (CM):1.7-2.0; Materiel de bande:Cuir; Poids Net (kg):0.069; Diamotre du botier approx (CM):4.5; Calibre:Japon PC





For make-up, skin-care and anti-aging products, please click here




Some good beauty care and health care products

Balance point - A blending of all vitamins, minerals and anti-oxidants you need to be healthy - This blending of vitamins, minerals and tissue-protecting anti-oxidants do not only contain those nutrients you find in the usual commercial vitamine and mineral products, but the formula also provides all these substances you need in tiny measures, and therefore is often forgot to include in the usual products. Furthermore it contains several natural substances that are not vitamins and minerals in the strict sense, but has shown to make the body work better and give enhanced energy.

Click here to learn more or buy - Multivitamin: Balance Point for Men

Click here to learn more or buy - Multivitamin: balance Point for Women


Instantwriclereduser - a serum for the skin to instantly reduce wrincles and give it a smooth young look - This topical serum contains a peptid that works in the same way as botox. It makes wrincling cramps in the fine muscles under the skin cease. The serum also helps the skin to ratain moisture better, which also takes away wricles. The full effect lasts around 8 hours.




To get strong allertness, stromg thinking agility and excellent memory functions - Brain Pills - These pills contain natural nutritions and stimulants for the brain power and to recuperate from brain weakening due to age, exhausting daily life or faulty nutrition. The pills will make you more allert, better to concentrate, remember better and better to solve problems.




StrawberryNET.com - All products of all major brands of cometics, make-up and skin care for favourable prices




An effective and clinically verified cream to reduce scars and consequences of skin injuries




An effective and clinically proven cream to reduce wricles and aging signs




Natural products to rejuvenate your skin, your body appearance and your physiology - Please choose that of the following good and clinically tested rejuvenation products that fits your need best. By going through the links you will find a thorrough decription of each product.:

A generally working natural rejuvenation drug:



Drug to stimulate rejuvenation of the skin.



A product for men to achieve a more vigorous production of male sex hormones, that can increase the sthrength of all sexual functions, make a man feel more vigorous and make it easier to build muscles:



A natural drug for men from the middle ages and above to reestablish capacities of the sexual life:




VigRXPlus - Capsules for men based on herbal extracts to stimulate the penis to erect longer and thicker, to increase the potency for erection all day and night and to increase the good sexual drive and feelings in the intimate parts and the mind - please click here


Provestra - Herbal capsules for women to enhance the sexual drive and good feelings in the genitals, to make the clitoris and vulva engorge better during excitement, to make more lubricating secretions, enhance potency for orgasm, reduce distress in heavy periods like the menstruation, and give these effects all day and night - please go here




Useful information

About noble metals

Properties and definitions about gemstones

Chemistry and physics of gemstones

About the minerals and gemstones in the quarts group - down at this page

Gemstones in the corundum group - rubines and saphires - down at this page

Beryl group gemstones, garnets, topaz

What characterizes dive watche

Tourmaline group gemstones

Lapiz lazul

How does gemstones get their colours

About perls and nacre




The quarts group of gemstones

Minerals in the quarts group are perhaps the most abundant minerals on earth. The great mountains on earth are partly made up of quarts. These minerals have a simple chemical composition. They consist chemically of silicone and oxygen atoms bounded together in a crystal or glass matrix, and have the chemical formula SiO2. Even though quarts minerals are very common and cheap, good specimens of quarts minerals are very fine gemstones.

Crystallic quarts minerals are fairly hard, grade 7, grade 10 is the hardest possible. The group consist of the following special kinds of minerals used in jewelry or as material in other finer utensils.

Ordinary white corny quarts: This is the most abundent form of quarts, and is most often simply called quarts. It consists of colourless small crystals lumped firmly togeather forming big white, corny, transcucent specimens. Ordinary quarts may look like marble, and is often mistaken for marble.

Corny quarts with other colors: Corny masses of quarts can show many colors. Brown variants are often called smoke quartz. Variants with reddish color is usually called rose quartz. These variants are like the white quartz not transparent, but only translucent.

Aventurine: This is a noble rock art mostly composed of corny quartz. There are also small flat grains of other minerals with a metallic shimmer, for example the crom-compound fuchsite, giving the whole stone a metallic green or blue shine. The basic color of aventurine is most often green, but it can also be orange, brown, yellow or gray.

Rock crystal: This is big and clear crystal of quarts. They are fine to form with facets like a diamond. A cut rock crystal does not look like a diamond, but has a beauty of its own caracterized by a special kind of transparent clearity.

Citrine: Citrine is a big and transparent crystalsof quarts with red, yellowish or brown colour substances. These substances often contain iron ions.

Amethyst: This is is big and transparent crystal of quarts with violet substances blended into the crystal matrix.

Quartz crystals with other colors: Big quartz crystals can show any color. Those with brown color are usually called smoke quartz, and those with reddish color rose quartz, just like the colored corny quartz masses.

Calcedon: A specimen of calcedon consists of a myriad of microscopic crystals. Calcedon is translucent and have a uniform greyish or grey-blue color and show a calm silky luster. Calcedon grows inside cavities by gradual crystallization from a watery solution. The center of the specimen is often still hollow, and the innermost layer often consists of rock crystal.

Agate: An agate specimen consists as calcedon of microscopic crystals, and is therefore not transparent, but is to some extend translucent. The specimen has concentric colour bands deposited one at the outside of the other. Agates have been formed in cavities in rocks, and the bands of the agate has been gradually cystalized onto the walls of the cavity from water in the cavy. The colour bands can be brown, red, blue, grey, orange and any blending of these colours.

Onyx: An onyx specimen also consists of microscopic crystals and is only to some extend translucent. An onyx has coloured layers stacked upon the top of each other, but the layers lay more regularly and parallelly than in ordinary agate, and there tend to be only few layers. All the layers together often bow in a wavelike fashion. Most colors can occur in onyx, except blue or purple. Black or white layers are common. An onyx specimen have been formed by crystallisation from water solutions in rock cavities, like the agate.

Jewelers often cut out pieces with specific colors and use these as gemstones, especially in rings for men. In the jewelry trade the name "onyx" is most often used about Such pieces in black or other specific colors. The term "onyx" is also used about marble-related rock types, which are not quartz-related, with the same pattern of stacked multicolored layers. This material which often shows shades of green is commonly used in artworks.

Carneol: Also a carneol specimen consist of microscopic crystals. Carneol is deep red and nearly not translucent at all. Also this type of quarts has been gradually crystallized from water solutions.

Opale: Opal is not crystalline, but has a glassy structure. The glass have small water drops blended into its structure, and this water causes interference and light breaking, making the opale show up a lot of colours that vary according to the angle of light falling into the stone.

Obsidian: Obsidiane is a glass formed when magma cools in vulacoes. Obsidian often contain small gass bubbles, soluted coloured substances or impurities. Obsidian can be transparent, translucent or totally opaque. The colour is mostly green, white or whitish.




The corundum group of gemstones

Minerals in the corundum group has a very simple chemical compositionm, being an oxyde of aluminium, with the formula Al2O3. Corundum is found as barrel-formed crystals. Corundum is the second hardest mineral on earth, having a hardness grade of 9. Corundum and corundum genmstones can be made syntetically by melting aluminium in a flame of burning oxygen-hyrogen with a surplus of oxygen.

Corund that do not have gemstone quality is widely used as abrasives and polishing tools.

Corundum often contain disolved elements giving colour to the crystal. Corundum without distinct inclusions and without uneven colour is used as gemstones. Corundum crystals of a distinct colour are more valuable than clear crystals. Corundum gemstones most often originate from the far east, for example Thailand, Burma and Sri Lanka. There are the following types of crundum gemstones:

Ruby (rubine, rubin ): Red corundum is called ruby, and is considered the most valuable corundum gemstone. The colour may vary from deep red, often found in rubys from Thailand and Burma to lighter red often found in rubys from Sri lanka. Rubys red as blood from a pidgeon are often considered the most valuable. Big rubys of good colour quality and without macroscopic inclusions are very rare, and these may get nearly the same prize as diamonds of the same size. The red colour of a ruby originates from disolved chrome.

Blue Saphire: Corund of blue colour is called saphire. Blue saphire is mostly called only "saphire" The blue colour originates from small amounts of iron and titanium.

Saphire of other colours: Green, yellow, clear or orange corund of gemstone quality is also called saphire.




Some more information about rubys

Ruby is a red gemstone that varies from a light pink to a blood red, a variety of the mineral corundum (aluminium oxide). The color is caused mainly by chromium. Its name comes from ruber, Latin for red. Other varieties of gem-quality corundum are called sapphires. It is considered one of the four precious stones, together with the sapphire, the emerald and the diamond.

Rubies are mined in Africa, Asia, Australia, Greenland, Madagascar and North Carolina. They are most often found in Myanmar (Burma), Sri Lanka, Kenya, Madagascar, and Cambodia, but they have also been found in the U.S. states of Montana, North Carolina and South Carolina. The Mogok Valley in Upper Myanmar has produced some of the finest rubies but, in recent years, very few good rubies have been found there. The unique color in Myanmar (Burmese) rubies is described as "pigeon’s blood". They are known in the trade as “Mogok” rubies. In central Myanmar the area of Mong Hsu also produces rubies. The latest ruby deposit to be found in Myanmar is situated in Nam Ya. In 2002 rubies were found in the Waseges River area of Kenya. Sometimes spinels are found along with rubies in the same rocks and are mistaken for rubies. However, fine red spinels may approach the average ruby in value.

Rubies have a hardness of 9.0 on the Mohs scale of mineral hardness. Among the natural gems only diamond is harder (Mohs 10.0 by definition).

All natural rubies have imperfections in them, including color impurities and inclusions of rutile needles known as "silk". Gemologists use these needle inclusions found in natural rubies to distinguish them from synthetics, stimulants, or substitutes. Usually the rough stone is heated before cutting. Almost all rubies today are treated in some form (of which heat treatment is the most common practice), and rubies which are completely untreated and still of excellent quality command a large premium. In general we can list the following types of improvements: color alteration, improving transparency by dissolving rutile inclusions, healing of fractures (cracks) or even completely filling them. See Treatments below.

Prices of rubies are primarily determined by color (the brightest and best "red" called Pigeon Blood Red, command a huge premium over other Rubies of similar quality). After Color follows clarity: similar to Diamonds, a clear stone will command a premium, but a Ruby without any needle-like rutile inclusions will indicate the stone has been treated one way or another. Cut and Carat (size) also determine the price approximately like clarity does



A rouby crystal



(The above picture and information is mostly from wikipedia.org, and therefore free for reuse)




Some more information about opals

The mineraloid opal is amorphous SiO2·nH2O, hydrated silicon dioxide, the water content sometimes being as high as 20% but is usually between three and ten percent. Opal ranges from clear through white, gray, red, yellow, green, shore, blue, magenta, brown, and black. Of these hues, red and black are the most rare and dear, whereas white and green are the most common; these are a function of growth size into the red and infrared wavelengths—see precious opal. Common opal is truly amorphous, but precious opal does have a structural element. The word opal comes from the Latin opalus, by Greek òpalliòs, by Sanskrit upálá[s] for "stone", originally a millstone with upárá[s] for slab.[2] (see Upal). Opals are also Australia's national gemstone.

Opal is a mineraloid gel which is deposited at relatively low temperature and may occur in the fissures of almost any kind of rock, being most commonly found with limonite, sandstone, rhyolite, and basalt.

Opal is one of the mineraloids that can form or replace fossils. The resulting fossils, though not of any extra scientific interest, appeal to collectors.

Precious opal shows a variable interplay of internal colors and does have an internal structure. At the micro scale precious opal is composed of silica spheres some 150 to 300 nm in diameter in a hexagonal or cubic closed-packed lattice. These ordered silica spheres produce the internal colors by causing the interference and diffraction of light passing through the microstructure of opal (Klein and Hurlbut, 1985, p. 444). It is the regularity of the sizes of the spheres, and of the packing of these spheres that determines the quality of precious opal. Where the distance between the regularly packed planes of spheres is approximately half the wavelength of a component of visible light, the light of that wavelength may be subject to diffraction from the grating created by the stacked planes. The spacing between the planes and the orientation of planes with respect to the incident light determines the colors observed. The process can be described by Bragg's Law of diffraction. Visible light of diffracted wavelengths cannot pass through large thicknesses of the opal. This is the basis of the optical band gap in a photonic crystal, of which opal is the best known natural example.

Precious opal consists of spheres of silica of fairly regular size, packed into close-packed planes which are stacked together with characteristic dimensions of several hundred nm.In addition, microfractures may be filled with secondary silica and form thin lamellae inside the opal during solidification. The term opalescence is commonly and erroneously used to describe this unique and beautiful phenomenon, which is correctly termed play of color. Contrarily, opalescence is correctly applied to the milky, turbid appearance of common or potch opal. Potch does not show a play of color.

The veins of opal displaying the play of color are often quite thin, and this has given rise to unusual methods of preparing the stone as a gem. An opal doublet is a thin layer of colorful material, backed by a black mineral, such as ironstone, basalt or obsidian. The darker backing emphasizes the play of color, and results in a more attractive display than a lighter potch. Given the texture of opals, they can be quite difficult to polish to a reasonable lustre. The triplet cut backs the colored material with a dark backing, and then has a cap of clear quartz (rock crystal) on top, which takes a high polish, and acts as a protective layer for the comparatively delicate opal.



An opal armband




(The above pictue and information is mostly from wikipedia.org, and therefore free fro reuse)