Sapphire resource distribution

Ceylon Island (formerly known as Sri Lanka) is the earliest country to mine sapphire in the world. Sapphire deposits discovered at present are mainly concentrated in Asia, and there are also sapphires in Africa, Oceania and South and North America (Figure 5- 15). See Table 5-4 for the distribution of major sapphire deposits in the world.

Figure 5- 15 Distribution Map of Major Sapphire Producing Areas in the World

Table 5-4 Distribution and Discovery Schedule of Major Sapphire Deposits in the World

sequential

(1) Asia

Asia is the most traditional sapphire producing area, mainly distributed in Southeast Asia (Figure 5- 16, Figure 5- 17). Kashmir, Myanmar, Sri Lanka and Thailand have been the main producing areas of high-quality sapphires for centuries. Although the output has fallen sharply in recent years, there is still demand for sapphire production in the market. In addition, sapphires are also produced in Viet Nam, China, Cambodia, Laos, Pakistan and Afghanistan.

1. Kashmir sapphire

Kashmir sapphire is the most precious sapphire in the world, with high blue saturation and velvet texture, which is as famous as Gumu Ruby and Colombian Emerald.

Sapphire was first discovered in Kashmir in 188 1 year, located in a valley under the snow line of Himalayan branch. Due to the harsh geographical and climatic conditions and territorial disputes in Kashmir, it is quite difficult to mine sapphire. Kashmir sapphires were all found in the mountains by local people who risked their lives. Since 1927, the sapphire mining in Kashmir has gradually entered the intermittent mining stage. Although the Kashmir government has a plan to lease sapphire mines every few years, it has not been really implemented so far. In recent years, the quality of sapphire produced in Kashmir has generally declined, and it is difficult to see high-quality sapphire with velvet texture.

Figure 5- 16 Distribution Map of Major Sapphires in Asia

Figure 5- 17 Distribution Map of Major Sapphire Mining Areas in Southeast Asia

From 1979 to 2008, * * 150 top sapphires were auctioned, of which 12 1 was Kashmir sapphire, and the auction price was as high as 39,000 ~135,000 USD /tc. At an auction in 2009, a 16.65ct Kashmir sapphire sold for 2.396 million US dollars, equivalent to144,000 US dollars /ct, which proved the charm and value of Kashmir sapphire (Figure 5- 18).

2. Burmese sapphire

Myanmar is a traditional sapphire producing area, and new mining areas have been discovered in recent years. The earliest record of corundum gemstones in Myanmar is 1597, and large-scale mining of rubies and sapphires has begun in Gumu area. Ancient animal husbandry mainly produces high-quality rubies and pink sapphires, as well as a certain number of blue sapphires. Sapphire with cereal has high transparency, good quality and good color. High-quality blue sapphires are comparable to Kashmir sapphires and are often called "sapphire" (Figure 5- 19). In addition to blue, more than 20 kinds of sapphires such as purple, purple, colorless and yellow are also produced in the ancient pastoral areas of Myanmar. Among them, yellow sapphire is relatively light in color and rare, and the famous green sapphire is extremely rare. However, large particles of red and sapphire and starlight red and sapphire are often found in this area. Generally speaking, Myanmar sapphires are brightly colored.

Sumeng sapphire mine was discovered in the 1990s. Its output is not as good as that of Gu Mo mining area in color and quality, but it has a large output. In the mid-1990s, it quickly became the largest sapphire producing area in Myanmar. But in recent years, the output began to drop sharply.

In 200 1 year, rubies and a small amount of sapphires were found in South Asia of Myanmar (adjacent to Pagan). Ruby and sapphire are pure in color, but the particle size is small, mostly less than 2ct.

Figure 5- 18 Typical Sapphire in Kashmir

Figure 5- 19 Typical Sapphire in Myanmar

3. Sri Lankan sapphire

Around 325 BC, sapphire was introduced to Europe from Sri Lanka, and was then called Ceylon. Zabala and Muwa provinces in southern Sri Lanka are the main producing areas of sapphire, and there are also many sapphire deposits in the upper reaches of the Carani River flowing through Muwa province. At present, sapphires of various colors (Figure 5-20) and a small amount of rubies, including the rare orange-pink "Padma" sapphire, can still be found in river beds or other sand mines in Sri Lanka. In addition, Sri Lanka is also a major producer of starlight red and sapphire.

Although the color of sapphire in Sri Lanka is light, it is very rich and of very good quality, especially orange and yellow sapphires. The highest quality sapphire is pure in color, high in saturation and moderately strong in brightness (Figure 5-2 1). Ruby in the true sense is very rare in Sri Lanka. The common red-toned corundum in Sri Lanka is called "pink sapphire" or "purple sapphire" in gem trading. The high-quality high-saturation orange-pink sapphire produced in Sri Lanka is called "Padma", which is a very beautiful and precious gem. Compared with Myanmar's starlight sapphire, Sri Lanka's starlight sapphire has a flexible star line, but its color and quality are slightly lower.

In addition to producing high-quality colored sapphires, Sri Lanka also produces a large number of white corundum-Gaida sapphires. In the 1970s, Thai jewelers discovered that this low-value white sapphire could be turned into a beautiful and transparent blue sapphire when heated. Subsequently, Thai businessmen began to buy large quantities of Chad sapphire and heat it in Thailand.

Figure 5-20 Original Stone of Sapphire Alluvial Deposit in Sri Lanka

Most Sri Lankan sapphires need heat treatment, and there are very few untreated Sri Lankan sapphires on the market at present. The data show that from 2006 to 2007, the output of sapphire in Sri Lanka decreased by 66.9%, from 47,000 ct/ year to 654,380,560 ct/ year, but the unit price per carat increased by 65,438+08.9%.

4. Thai sapphire

Before the discovery of Kashmir sapphire, Thailand was always the most important producer of sapphire. In the mid-1930s, Thai sapphire accounted for about half of the world sapphire market. The main producing areas of sapphire in Thailand are Chien Chuen Phu, Datuk Phu and Pak Phu Phu, and the output of these three mining areas accounts for 90%~95% of the total sapphire production in Thailand. Among them, Jianwenfu mining area and Dadai mining area are located in the same gem metallogenic belt, which are similar in geological environment, metallogenic model and gemological properties.

Fig. 5-2 1 high quality sapphire from Sri Lanka

The earliest sapphire mining area in Thailand is KhaoPhloiWaen mine in Chienchuan, which was earlier than 1830. At the beginning of the 20th century, a series of rubies and sapphires were discovered in Jianwenfu and Dade. By the 1990s, * * * had about 40 mining areas.

Sapphire in Beibifu has always been famous for its large particles and bright colors. At the end of 19, manual small-scale mining began. After more than a century, the company introduced mechanized equipment for large-scale mining, and then the output increased rapidly. However, in the mid-1990s, the output began to decline. From 1995 to 2005, the average annual output was less than 200kg.

Sapphire in Thailand is generally dark in color. In addition to blue, there are green and light yellow (Figure 5-22). There is also black star corundum, which has a large output. Most dark blue sapphires in Thailand can only be sold after high temperature discoloration.

Figure 5-22 Sapphire rough stones of various colors in Thailand

Figure 5-23 Distribution of Main Sapphire Mining Areas in Vietnam

5. Vietnamese sapphire

Ruby deposit was first discovered in Vietnamese marble in 1983, located in Lv Qin, 270km northwest of Hanoi. By the end of 1994, the mine had no commercial value, so its mechanized mining was stopped. Ruby and a small amount of blue and pink sapphires in Lu 'an Mine are generally bright in color, but their clarity is low.

Corundum is also produced in Quzhou, which is more than 0/00 km south of Lu 'an/KLOC. The third corundum producing area was found in 1994, located in TanHuong, 80km south of Lu 'an (Figure 5-23).

The colors of sapphires produced in these three places are orange, blue and purple, but the output of sapphires is much lower than that of rubies.

In the 1990s, some small sapphire deposits were discovered in the northern and central regions, with little output. Sapphire production in Vietnam is unstable. The output of corundum mine in Vietnam was very large for several years, and then the output dropped sharply, which could not meet the requirements of commercial mining. 1996 produced about 40kg, and reached 1700kg two years later, and decreased to 70kg in 200 1 year. In 2006, these mining areas were mainly mined by local people, with low output.

6. China sapphire

The first sapphire was discovered in Hainan in 1960s, but the sapphire mines in China are mainly concentrated in the east of Shandong Province. 1985, 7 sapphires were found in Shanglin placer mine in Linqu, Shandong Province. Subsequently, during the period of 1986~ 1990, Shandong Provincial Bureau of Geology and Mineral Resources delineated many rich mining areas such as Wutu and Beiyan in Changle, and discovered primary mines in Fangshan and Qiujiahe.

Figure 5-24 Shandong Changle dark blue sapphire

Shandong sapphire is dark in color (Figure 5-24), which is similar to Australian sapphire. In addition, there are some green, blue-green and yellow-green sapphires. The crystal morphology of Changle sapphire is relatively complete, with large particles, the particle size is generally above 1cm, and the weight is 15~30ct, and the largest can reach several hundred carats. The colors are mainly blue, indigo, green and yellow, and there are starlight varieties.

7. Sapphire from Cambodia and Laos

Berlin, Cambodia is famous for producing gem-grade sapphires, which is located near the border between Cambodia and Thailand. In 1950s and 1970s, due to the war, the news of sapphire production in Cambodia was never announced to the outside world, and it was not until 1978 that the sapphire from Berlin was known to the world. The quality and color of Cambodian sapphires are second only to Myanmar, but few large-grained gems are produced. Sapphire mining in Berlin stopped in 2002.

The sapphire mine in Laos was discovered in the 1990s of 19, and the mining area is located in a place called BanHouayXai at the junction of Laos, Thailand and Myanmar. But it was not until 1995 that systematic mining began, and the sapphire produced was dark in color. By 2005, only a small amount of artificial mining activities had been carried out.

8. Sapphire from Pakistan, Afghanistan and Central Asia

Besides the famous and traditional Southeast Asia, corundum is also produced in Pakistan and Afghanistan in the Middle East. Although these areas mainly produce rubies, there are also a few sapphires. For example, Wardak province in Afghanistan produces blue sapphires; There are purple sapphires in Basha Canyon, Pakistan. Nepal produces some pink and purple-blue sapphires.

(ii) Africa

Sapphire mining area in Africa was discovered later than several famous mining areas in Asia. In recent years, the proportion of African sapphire in the market is increasing. The following will introduce the main producing areas of East African sapphire: Tanzania, Kenya and Madagascar (Figure 5-25).

1. Tanzanian sapphire

Tanzania is a major producer of rubies and sapphires in Africa. Sapphire is mainly produced in the eluvial deposits of basic eruptive rocks and proluvial. The particle size ranges from 0.5~5cm to 5cm, and the color is mainly blue. Sapphire production in Tanzania is very large, reaching several tons. The color depth is between the dark blue of Shandong sapphire and the light blue of Sri Lanka. The number of inclusions is also uncertain. There are many inclusions that can be cut into curved surfaces, some rough stones can be processed into faceted gems with clean interior, and a small amount of them have starlight effect. Tanzania also produces white "Chad" sapphire, which can be turned into transparent and bright blue sapphire after high temperature.

Figure 5-25 Distribution Map of Major Sapphire Producing Areas in Africa

At the end of 1994, sapphire placer was found in the riverbed near Tongduru, Tanzania. Subsequently, this area became one of the most important gem producing areas in East Africa. The colors of sapphires are pink, yellow, blue, purple, green and color-changing sapphires. Subsequently, another corundum deposit was discovered near Songgaia, west of Tongdulu 140km, and the sapphire produced by the two deposits was similar. With the discovery of a large gem mine in 1999 Irakaka, Madagascar, the mining activities here have obviously decreased.

In 2007, a new mining area was discovered in Wenza, central Tanzania. There are both primary and secondary mines in this mining area. Besides blue and red, there are also varieties of blue and red corundum. Sapphire is of good quality, and most of it can be sold in the market without heating treatment.

2. Kenya sapphire

Kenya mainly produces rubies and a small amount of sapphires. JonhSaul mine in Mangari region has become the most important ruby mine with the highest output in Kenya. Other mining areas include Baringo discovered in north Nairobi in 2005 and Simba discovered in 2007. However, the ruby production in these two mining areas is not large.

3. Madagascar sapphire

In recent 20 years, Madagascar has become the most important sapphire producing area in the world. From 1993 to 1994, only a small amount of corundum was found in Madagascar, but a very beautiful sapphire was found in the area of Andranondambo in the southeast of the island (Figure 5-26). Later, it was found that the sapphire resources in Andhra Nudambu were very rich. In the following three years, about 1.200 kg of sapphire was transported to Thailand every year, and many faceted gems of 1.5 ~ 20 mt were processed. A considerable number of gems have been heated, and the treated sapphire can be comparable to Kashmir sapphire.

1996, an influential sapphire mine was discovered in Antsiranana, the northernmost part of Madagascar. In the following two years, the region became the largest commercial sapphire mining area in the world, with about 1 10,000 workers digging by hand, and gem merchants from Thailand and Nigeria traded here. By 1998, the government temporarily banned mining activities. However, a larger sapphire mine was found near a small village called Irakaka, and miners and jewelers moved to Irakaka.

When Thailand's sapphire resources were almost exhausted and Australia's output dropped sharply, the Irakaka mining area was discovered. The output of this mining area is very high, and the entry of 65438-0999 into the market has a timely supplementary effect on the sapphire market. Besides the advantages in quantity, some blue sapphires in Irakaka are also beautiful, and the color of colored sapphires can be compared with the best colored sapphires in Sri Lanka. 2/kloc-0 At the beginning of the 20th century, Irakaka's pink sapphires led the trend of colored sapphires. Around 2005, Irakaka became one of the largest sapphire deposits in the world, and the sapphire in Madagascar has accounted for about 50% of the sapphire in the international market.

Figure 5-26 Madagascar colored sapphire

(3) Oceania

For Oceania, the main sapphire mining areas are concentrated in Australia (Figure 5-27). Australian sapphires are mainly produced in two states: New South Wales and Queensland. 185 1 year, the Australian sapphire mine was first discovered in CudgegongRiver and MacquarieRivulet basins in New South Wales. 1854, another important sapphire mining area was discovered in Foehrer. Among them, the KingsPlains mining area, located in the northeast of Foehrer, is considered to be the region with the richest gem-grade sapphire reserves in Australia.

As the largest mining area in Australia, Anakie mine in Queensland was discovered in 1970s. /kloc-started mining in the 1990s in 0/9, and has been mining for the next ten years, but the output is unstable. The output was very low in the 1930s and 1960s; Sapphire mining rose again in the mid-1960s, probably because the appearance of heat treatment technology in Thailand improved the color of Australian sapphire. Another sapphire deposit in Queensland is located in LavaPlains. The mining area produced a large number of sapphires in the 1980s and 1990s.

From 1970s to 1980s, Australian sapphires accounted for about 70% of the world market. Most of them are low-quality and cheap sapphires, while high-quality Australian sapphires are usually labeled as "Thailand", "Sri Lanka" or "Cambodia". In fact, as early as the early 20th century, Australia has become the world's major sapphire producing area. After the First World War, the output of Australian sapphires declined, and most of them were dark in color and contained many cloud-like inclusions, so they were not suitable as gems. In 1960s, with the improvement of the heat treatment method of Thai sapphire, the color of Australian sapphire became lighter before it entered the market again. From 1995 to 2005, the output of Australian sapphire dropped from about 13000kg to about 5500kg, a decrease of about 60%, but still far higher than other producing areas.

Figure 5-27 Distribution Map of Major Sapphire Producing Areas in Australia

(4) America

There are many sapphire deposits in the United States, the most famous of which is Montana (Figure 5-28). There are three main placer mines in Montana-Missouri River, Dry White Yangxi River and Locke River, and there is also a primary mine-Yogo. 65438+In 1960s, Montana sapphire was discovered as a by-product of gold mine. 1865, sapphire was found in the sand mine of Missouri River, but it was very light in color and some of it had a green tone, which did not attract people's attention at that time. Later, sapphire was found in other places, Ganyangmuxi mine was discovered in 1889, and Yanxi mine was discovered in 1892.

1895, Montana's high-quality Yogo sapphire first appeared. Yogo sapphire has a uniform blue color (usually described as "cornflower blue"). Yogo sapphire mine has the largest output among the four mining areas. From 1994 to 1996, Yogo alone produced more than 4 million ct of gem-grade rough stones. The faceted gems of these rough stones after cutting and polishing exceed 654.38+00,000 ct. During this period, Montana became the largest sapphire producer in the world. Now the mining activities in Yogo are gradually decreasing. Most sapphires from Yogo mine need heat treatment, and after heat treatment, they can obtain very high-quality colors. After heat treatment, Montana sapphire is widely developed and used as a gem. Montana sapphires are rich in colors, including orange, pink, purple, green, blue-green and gold.

Sapphire deposit in the United States Apart from the United States, another important deposit is located in Brazil, South America. As a traditional producing area of colored gems, sapphire deposits in Brazil rarely produce gem-grade sapphire.

Figure 5-28 Distribution Map of Major Sapphire Mining Areas in the United States