加工...

Australian Black Opal Information

澳大利亞黑歐泊信息

該文本是機器翻譯的。 顯示原件？

Highly prized and sought after by kings, emperors, maharajas and sultans, the majestic opal has been desired throughout the ages. Its intrinsic beauty and ever-changing colours and patterns keep those who poses it spell bound. Many historic opals were crystal which tended to produce milky white colours not the bright flashes as the Black Opal above. The discovery of black opal in Australia in the late 1800’s with its bright colours changed the gemstone world. This new black opal became to be known as the ‘Queen of Gems’.

Lightning Ridge is the home of the beautiful black opal. It is nestled away among high ridges covered with scrub and pebbles. It is here that eons ago, nature hid the earth’s rarest gem, black opal. The beauty of the green trees, blue sky and red pebbles is reminiscent of the ever-changing colours of the magnificent opal found deep below. Unlike other gemstones no one opal is the same.

SPEC the black opal dog miner Lightning Ridge 1990

Lightning Ridge, however, was not the first place to report black opal. It had been found in Egypt in 1899, two years before Jack Murray sank the first hole at the Nobby in 1901, at Jundah, Queensland and later at White Cliffs. But Lightning Ridge opal was different, and it is this difference that has made it famous. Until that time, the world had never seen such incredible patterns in opal on such a beautiful black back. The supply of black opal from Lightning Ridge dramatically changed the way gem merchants evaluated opals, setting an unprecedented hallmark for the gem. Black opal is the rarest and most valuable of all opals and is generally found as a bar of various colours in a dark body. In addition, there is also semi black and black crystal. Lightning Ridge in New South Wales is the worldwide home for black opal and is widely regarded as producing the best black opal in the world.

Australian Black Opal Mining

Black opal is getting harder and harder to find. Not only have fuel prices and lease fees made it very costly to mine for opal, but the scarcity of Black Opal is now a reality. This trend has been emerging for years, and it is now rare to find quality red fire black opal. The majority of opal being mined at Lightning Ridge is now seam opal, which is formed in bands similar to opals from Coober Pedy. Black opals that have formed as nuggets are now rare to find. Even the color base of black opals is different to years ago; the natural base is now more of a grey black color rather than dark black as it used to be. Miners are finding much more semi-black opal. Black opal color guides can be used to grade the darkness of a Black Opal. N5 is the darkest, and Hi the lightest.

Black Opal Investment

Black opal have always been the informed buyers top choice when selecting gemstones for investment. They have a strong red fire and a dark black base are considered extremely rare and as an investment will generally appreciate by at least 20% per year.

Many black opals sold on Opal Auctions have increased in value between 20 and 30% per year and some black opals valued at $1000 per carat have now increased to $3000 per carat. Investors in black opal should always look for top opals that have a black base.

Other factors include-

• Cabochon shape (domed tops are ideal for Jewelry)
• Uniqueness of the pattern and color. Red is most valuable but some orange and green fire ribbon patterns can also make for excellent investments.

Black opals have always been the favourite type of opal for serious collectors, but boulder opal has increased in popularity as well. The Japanese market tend to prefer black opal cabochons and have helped moderate an ongoing value increase for this opal type. One of our most expensive Australian Black Opal ever sold on Opal Auctions is a 37.30 carat Black Opal sold by Rollingstone Opals for $37,500. It is a gem fire Black Opal with body tone N1 and brightness rated at 5 out of 5.

Australian Black Opal Availability

There are a few spectacular opal collections in Australia but none that include a large Black Opal collection because they are so rare. This trend is repeated overseas, where large Opal collections can be found in several countries including the US, Hong Kong and Germany but a large collection of black opal is very rare indeed.

Black Opal Market Trends

With the ever increasing cost of opal mining mainly driven by oil prices and dwindling availability, the opal mining industry is coming under more and more pressure.

In Lightning Ridge all the “easy” mines have already been exhausted, and miners are facing very tough and dangerous mining conditions to extract opal in the more dangerous mines. Low grade black opal is steady and available so the common laws of supply and demand are in force.

Opalholics - now is the time to buy investment opal because the supply of high grade black opal is thinning, and the mining community of Lightning Ridge as a whole is not finding much opal, which can only mean one thing for prices.

How Black Opal is Graded and Sold

How would you set this black opal? As ring or pendant? If pendant which way would you face this opal ABCD? Opals have lot more decisions required than any other gemstone as each one is so unique and special.

Black Rough Opal parcels are sorted into three grades: tops, middle, and low. Each tops parcel has a King stone,which is the best stone in the parcel. Some parcels have several King stones. Color is the primary criteria for grading, but the graders also take into consideration the number of imperfections and faults, and whether a stone is the right shape to be cut into an oval or one of the other popular shapes. You can buy rough opal in several different conditions.

Mine Run. Direct from the opal mine. The stones have not been cut or ground down. This means that there is more guesswork in the cutting.

Purchasing mine run opal can be risky if you are not very experienced.

Off - Cuts. The miner has removed whatever opal he has a market for and sells you what’s left. With off cuts, you can usually tell what you are going to be able to cut. You must still watch for cracks in the opal because once a crack becomes obvious, a stone can lose half its value.

Rubs. This can often be the best way of buying rough if you are not very experienced. The miner has cut and ground the stones into basic shapes, after having removed most of the rubbish. What you have left is the stone nearly ready for the dopping and polishing process. You have the satisfaction of cutting your own stones without the high risk of buying mine run rough. Opal is officially sold in troy oz. There are approximately 30 grams to a troy oz and approximately 30-oz to a kilo.

Black opal mined from Lightning Ridge has always had good reputation for blue opals on black. These opals in the 1980s were common in the Cochran opal fields at Lightning Ridge and these were Nobby opals not seam opal, that is the opal was formed naturally in rock with black potch on top and bottom.

The seam opal has lighter black back and sometimes with grey or sandy potch on top. Black opal nobbies are best investment opal as from 1990s production of black nobbies has dramatically decreased and only seam opal is found today. We see less and less black opals with blue fire colours

Some blue opal from Lightning Ridge has magic electric blue fire and flash and also some best natural patterns of opals are in blue colour, from broad flash to block pattern and they are very attractive in white gold ring.

Black Opal Pairs

Black Opal Parcels

Black Opal Carvings

These days white gold jewellery is very popular and some crystal opals do not suit white gold jewellery but black opals blue colour are stunning, even set with diamonds they look so attractive to the eye, especially blue hues in a black opal. Black opal has promoted red fire opal as the best opal for investment.

Rating colour of black opals are as follows in regards to price per carat

• Red
• Orange
• Green
• Blue

However Blue opal has been under valued as investment opal, black opal with red fire has increased in value 50% per year over last 10 years. Black opal with cabochon and good flash has doubled that figure to make it the best investment colour if you had purchased blue fire opal 10 years ago

Also when purchasing opal over the internet always ask seller if opal is as bright as picture, so good idea to ask for picture of hand holding the opal as the picture cant be enhanced as the colour of skin looks different ,either greyish or pinkish looking means the picture has been enhanced

Opal is also rated in accordance to brightness. Body tone which is how the opal is visual is also measured from N 1as blackest to N9 as lightest opal. Also check with seller that the bottom of opal is clean, that’s is all natural potch ,black preferred to grey or if potch/sand is evident on bottom.

Lastly the more cabochon the opal also the more valuable, so flat opals are generally less expensive than well domed opals. Opals that are cabochon Jed reflect light better and rolling flash pattern is very popular as shows colour from all angles

Enjoy your own Black Opal!