Tips and Training
Gold is naturally yellow, but we get 3 main grades:
- the pink
- White (also called gray)
These grades are based on alloy metals used (silver, copper, nickel) Gold is extremely malleable and better the work, we must partner with other metals. In France, 750 / 1000th or 75% pure gold and 25% alloy, 585 / 1000th, 58.5% pure gold and 41.5% of alloy, 375 / 1000th, 37.5% pure gold and 62.5% alloy are allowed to be defined as gold.
By law, all structures containing gold or platinum beings are punched as soon as they have a weight greater than 3 grams.
Melting point of pure gold: 1064 ° C
Principal solvents: Mercury and aqua regia (hydrochloric acid + nitric acid)
This is a gold layer applied to a base metal by different surface treatments.
Silver is a naturally white precious metal gray. In France, there are two alloys: the 925/800 and 1000th / 1000th.
By law, all books containing silver have punched beings when they have a weight greater than 30 grams.
The size of the diamond makes the most of light and laws of propagation (reflection, refraction, dispersion), determining the proportions to give fire, sparkle and glitter.
The size is measured in carats and of course, the ideal is to have the carat the biggest and purest. The size is the most important factor in evaluating a diamond. A carat weighs 0.20g.
Follow these tips to keep the splendor of your diamonds:
Pour mild liquid soap in a small bowl of warm water. Clean the jewelry with an eyebrow brush in soapy water, then place them in a small tea strainer and rinse with warm water under the tap. Gently dry with a soft cloth.
Cold water bath:
In a cup, prepare a half and half cold water and ammonia solution. Soak the jewelry for 30 minutes before removing and gently clean around the crimp using an eyebrow brush. Dip them in a final solution, then blot with a tissue.
There are several small aircraft of this type on the market able to clean jewelry in minutes that can be immersed in liquid. Each model is slightly different, it is recommended to read the user manual carefully before using the device.
Sapphire is one of the most resistant stones.
With a hardness of 9 on the Mohs scale, sapphire is harder than all the other stones, except diamonds. This is the perfect stone for an engagement ring. This is also the stone has chosen Prince Charles to Princess Diana ring.
It owes its blue color in the presence of iron oxide and titanium. The sapphire color variations can range from white to pink through orange, gold, yellow, green, purple and violet. The most common size of the oval sapphire is best suited to the shape of the rough stone.
Corundum family or rather the oxidized aluminum crystal, which is one of the most resistant minerals. Corundum has a hardness of 9 on the Mohs scale.
The ruby is formed especially (but not exclusively) in marble, a metamorphic rock composed of calcium carbonate, which is formed at temperatures and under extremely high pressures.
Ruby is not extracted directly from the rock. Indeed, it is found in stony alluvium derived from erosion of the mountains.
Hardness of 7.5 to 8.0 on the Mohs scale
Emerald is the only stone of the family of Beryl, which is classified in the family of gemstones.
The color of emeralds from blue / green to green / yellow, through the whole range of soft and deep emerald green. It is the presence of chromium and iron which gives the green / yellow, and chromium associated with vanadium which gives green / blue.
THE FINE STONES
Hardness of 7 1/2 to 8 on the Mohs scale.
The most popular features of the aquamarine stone of the beryl family, is its transparency and size of its crystals. A piece of 110kg, perfectly transparent, was discovered in 1910.
The table-shaped cuts and stairs are most suitable because they highlight all the transparency of aquamarines.
The round stones, oval, pear or facets are also used and preserve as much splendor stones.
For non-transparent aquamarine, the best cut is the cabochon.
The main reserves are in Brazil, in the Urals, Namibia, Zimbabwe and China. In Madagascar, there are stones of a beautiful blue-gray.
Hardness 8 on the Mohs scale
Topaz is an aluminum silicate. It consists of aluminum, silicon and oxygen, but also fluorine and ion oxhydryle (group consisting of an oxygen atom and a hydrogen atom).
Topaz is usually cut in oval, classic shaped to showcase its different shades and light effects. But some jewelers prefer the rectangular size (with table and degrees). The cabochon (rounded dome base plate) is rare, it is often reserved for non-transparent gems or with inclusions.
The dark yellow topaz is a popular gem: it strongly resembles citrine, a variety of quartz.
The intense blue topaz is often used to imitate aquamarine stone to a higher value.
Many museums around the world pride themselves possess remarkable topazes. The largest known topaz (3270 carats) is preserved at the Smithsonian Institution in Washington. The British Museum houses meanwhile a 614-carat topaz.
Hardness of 7 on the Mohs scale.
Amethyst is the most popular stone quartz group. supernatural powers are attributed to him: it is a talisman that brings luck and strength, protection spells, the homesickness, not even of intoxication, as indicated by the Greek etymology of its name: "amathustein "(" not drunk ").
Historically, this stone is known for two main virtues: it protects the crops against insects and preserves the beauty of women.
Moreover, in the history of Christianity, amethyst, symbol of piety, was the only stone endorsed by the most powerful churchmen.
In heraldry, the science of heraldry, amethyst symbolizes modesty.
The beauty of amethyst lies in the very origins of the stone, which is often present in the cavities of rocks.
Abundant with dark purple amethyst deposits are found in Brazil, Uruguay and the Urals, while Mexico is renowned for its amethysts red-violet color. One can find other deposits in Sri Lanka, South Africa and Europe (France, Germany and Italy).
Hardness of 7 on the Mohs scale.
Sometimes confused with topaz, citrine is named after the lemon, "citrus" in Latin, which it has color. It belongs to the group of quartz.
This stone is found in different deposits, Brazil, India, Madagascar, Uruguay, Mexico and Sri Lanka.
Citrine is considered the equal of amethyst and rock crystal, although the latter two have historically been more used.
Citrine is suitable for all "small facets" cuts, and this rock has rarely inclusions.
Hardness: 7 - 7.5 on the Mohs scale
In Roussillon, around Perpignan, the use of garnet jewelery is perpetuated since the eighteenth century. At that time, the stones were extracted from the Pyrenean reliefs (Estagel, Caladroi, Costabonne, Espira of Agly, Latour-de-France and most likely alluvium Agly and its tributaries).
Currently, garnets mostly come from the Bohemian Massif where they pass through Idar Oberstein (Germany), where they are cut to form "rose". They are then mounted respecting an ingrained tradition in Catalonia.
Garnets are used in jewelry for thousands of years. In ancient times they were known as carbuncle or red gem.
Historically, garnets are supposed to protect wounds and poison, stop bleeding, symbolize truth and loyalty and bring prosperity.
Hardness: 6.5 to 7 on the Mohs scale
Peridot is also called Olivine and Chrysolite.
Small crystals of peridot are often found in volcanic rocks and in meteorites fallen on Earth.
It was called "gem of the sun" by the ancients. They believed he had the power to dissolve enchantments and ward off evil spirits. For peridot exercises its full powers, it had to be mounted on gold, and so worn he hunted the terrors of the night. If used as protection against evil spirits, peridot had to be drilled, past a donkey hair and worn on the left arm.
Powdered, peridot was used as a remedy against asthma and placed under the tongue was reputed to lessen the thirst created by fever.
Beautiful Peridot, brought from the Mediterranean by the Crusades, were used to decorate European cathedrals where we can still admire today.
Hardness of 7 to 7.5 on the scale of Mohs.
tourmalines were especially appreciated the under the Roman Empire especially as ornamental stones to beautify objects and jewelery, and were subsequently used for sacred art (see Treasury Duomo di Monza). They were introduced to Europe by Dutch sailors in 1700.
Tourmaline comes in many colors (including pink, red, green, yellow, violet, and blue) according to the following chemical elements: chromium, iron, titanium, copper, manganese, and vanadium.
The tourmaline reserves are scattered all over the world: Afghanistan, Brazil, India, Kenya, Madagascar, Mozambique, Namibia, Nepal, Nigeria, Sri Lanka, Tanzania, Zambia and Zimbabwe .
Hardness: 6.5 to 7 on the Mohs scale.
Jade is a Chinese stone, hard, translucent, with a very fine grain, smooth and very tight. It is smooth to sight and touch. Its color varies from creamy white to dark olive green. It can also become amber or reddish up to brown.
In China, women use Jade staples to close their dress silk, jade and jewelry are passed from generation to generation, from mother to daughter. The civilizations of all ages have appreciated this stone and all races who met bore him the highest consideration. In prehistoric civilizations, in the European region of Valtellina and Swiss Lakes, Guatemala and Mexico, she was appreciated for its hardness and used to make tools. Pre-Columbian populations were sacrificial knives. Among the Maori of New Zealand, a jade warrior club was the symbol of the authority of the head and in the islands of the Loyalty (New Caledonia), fathers exchanged their daughters against the jade.
Chinese popular tradition assigns several virtues: his touch brings, like amber, relaxation and recreation. When worn on the skin, it relieves the kidneys and strengthens the heart energy. Placed under the pillow, it provides a deep and pleasant sleep.
Jade fits all jewelry, both female and male.
In Europe, the jade mainly revolves around bracelets. It is presented in form and the most magical color: green and unclean. But the jade necklace can be worn (jade balls or raw jade) pendant lucky, and earrings.
Hardness: 5-6 on the Mohs scale.
Also called lapis lazuli, lapis is a semi-precious stone.
In ancient times, there was confusion lapis lazuli and sapphire. So Pliny sapphire with golden spots. There are similar references in the Bible.
In the past, the cost of a difficult route on land and sea added to the hard work function. Lapis lazuli was glitzy, more expensive than gold, which also explains its presence in jewelery and funeral masks of the Egyptian royal families.
In ancient Egypt, lapis was indeed a favorite ornamental stones to carve amulets (including beetles). The Babylonians and Assyrians also used it to make seals. At that time, the mines were located in Badakhshan, northern Afghanistan.
During Roman times, lapis was reputed to be an aphrodisiac.
In the Middle Ages was assigned him other medicinal properties: good for the robustness of the members, and preventing the spirit of fear, doubt and envy. We drank crushed, mixed with milk.
The lapis value have an intense blue color, dotted with yellow pyrite fragments. If they are too many, or if the stone contains white calcite veins, then it loses its value.
Lapis can be perfectly polite and it is widely used in jewelry.
It is also used to make mosaics, sculptures and ornaments.
Pearls are formed inside oyster marine mollusks like bivalves. They come from the reaction of these animals to foreign bodies that have slipped between the shell and the mantle of the oyster, and sometimes even within the mantle. These foreign bodies can enter naturally or artificially.
In the case of cultured pearls, whether white or color, the introduction is made by man. This complicated operation consists of introducing into the connective tissue of the mantle of an oyster fished offshore small spheres of polished pearl, wrapped in a piece of epithelium derived from the mantle of another pearl oyster.
In all cases, the introduction of an element in an oyster causes a natural defense reaction by which the foreign body is gradually covered with nacre and ultimately turns into pearl.
Pearls come in several colors: white, black, gray, or pink hues, yellow, or blue-gray.
The most common and the most popular are round pearls, Akoya oysters originating.
Australian and Tahitian pearls are larger and darker, steel gray or black color with green hues.