The Jones Diamond is a blue-white alluvial diamond that was discovered in Peterstown, West ia, way back in 1928. It spent the Great Depression hiding inside a cigar box in a tool shed, until in 1942, Punch rediscovered his stone and took it to a geology professor at ia Tech.

The alluvial diamonds are in a coarser size fraction range, from 2.3 to 5.6 mm. They are comparable to Collier-4 diamonds regarding their resorption degree and occurrence of macles (15 %) and aggregates (10 %). A total of 58 % of alluvial diamonds are dodecahedra, and 15 % are octahedral diamonds.

A significant scientific research focus since the 1980's has been on lithospheric diamonds, sourced from kimberlite mines; however, some of the first and most important discoveries of sublithospheric diamonds were made from the alluvial diamond fields of Australia (Ororoo), Brazil (Juina) and West Africa (Kan Kan) as described in Stachel et ...

The Punch Jones Diamond—also known as the Horseshoe Diamond —remains the largest alluvial diamond ever discovered in North America and the third largest found on the continent. Grover Jones, Sr., fathered 15 boys and a daughter, the youngest, in Monroe County. According to the late historian Shirley Donnelly, the gem …

Natural diamonds were formed some 3.3 billion years ago in conditions of intense heat and pressure 150km below the earth's surface. Alluvial diamonds were the first diamonds to be discovered in South Africa. Alluvial means these were diamonds that had been removed from their primary position by erosion over millions of years, and deposited in ...

These alluvial diamonds are recovered by placer and marine mining techniques that are very different from hard-rock kimberlite mining. Although these specimens are found "off-craton," they derive from "on …

The general principles that govern any search for alluvial diamonds, the processes involved in alluvial diamond deposition and the methods and technology …

This reading list was compiled to give you an opportunity to learn more about the history of alluvial diamonds from Namibia. A number of the articles were published …

Alluvial diamonds from Wellington, Bingara, Copeton, and Airly Mountain in New South Wales form two distinct groups, here termed A and B. Group A diamonds are similar to those found in kimberlites and lamproites globally and are thought to have formed in Precambrian lithospheric mantle. Group B diamonds have unusual characteristics …

assess the geological resource potential and the rough diamond. production capacity in Ghana. The speci c goals of this project are as follows: 1. Acquire and provide remote sensing imagery of ...

The discovery of diamonds in South Africa in the late 19th century also led to the establishment of large-scale alluvial diamond mining operations in the country. Nowadays, it is most commonly carried …

Inland, alluvial diamond production reached a recent peak of 1.23 million carats in 2003, providing employment for an estimated 25,000 people which then dropped to a disappointing 6,000 people in 2005. The discovery of the Lichtenburg diamond field in 1926 made a huge, short term impact on South Africa's diamond production but this …

Abstract. Since the mid-1950s the Kwango River has been a major target for alluvial diamonds which are and continue to be mined from its terraces, younger river flats and present-day river channel. The terraces have maximum ages of Early to Middle Pleistocene. Most of the diamonds have been recovered from large diamond placers in …

Similar alluvial diamonds are found in nearby Venezuela, Brazil, and Suriname, suggesting the Roraima is a common source. Indeed, these paleoplacers represent a regional diamond terrane with a lateral extent of at least 450,000 km 2. Diamonds from Guyana are of scientific interest because they are survivors of >2 Ga of …

The alluvial diamonds appear to have been sourced from the important northeastern Lesotho diamond field, which is the source of the bulk of diamond production in the Kingdom of Lesotho. The project has yet to be subjected to a systematic exploration and sampling programme. ExplorMine is currently actively seeking investment partners for …

The extremely low concentrations of diamond in most alluvial deposits and the almost random distribution of the diamonds within the gravels, necessitate the taking …

The diamond in the Gbenko alluvial deposits in Guinea (West Africa), mined by Aredor Guinee S. A., have a gem content of 93%. At present these have an average carat price close to US300, probably ...

The earliest diamonds in South Africa were also alluvial, but later diamonds were found in their host rock, kimberlite. Finding the host rock meant that diamonds could be mined in higher concentrations and greater quantities than before. This made large-scale open-pit mining worthwhile, transforming how diamonds are unearthed.

The extremely low concentrations of diamond in most alluvial deposits and the almost random distribution of the diamonds within the gravels, necessitate the taking of large samples in order...

Alluvial diamonds have been mined in most Brazilian states since the beginning of the 18th century, when the colony was still under Portuguese rule. Besides alluvial occurrences, there are other important deposits …

A methodology for conducting national-scale alluvial diamond resource potential and production capacity assessments, with a focus on artisanal mining: DOI: …

The alluvial diamonds associated with the gravel deposits in the Christiana, SchweizerReneke, Wolmaransstad and Bloemhof districts are generally of high quality, as a result of the presence of larger stones (50 to 200 ct). In recent years there have been important advances in the techniques used for the exploration of alluvial diamond …

The Woyie River rough diamond weighed 770 carats and was dubbed one of the largest alluvial diamonds ever to be found. And the Sergio diamond (3167 carats), weighing slightly more than the Cullinan, is a carbonado diamond, a rare black diamond. And most recently we wrote about the Lulo Rose, a 170 carat pink diamond.

Global Diamond Network 9 Challenges with Alluvial Diamond Mining Mentoring 01 Alluvial diamonds are challenging minerals to mine. 02 Very limited modern and reliable published information on Alluvial Diamond Deposits – very low grade, great price variability. 03 Most small to medium scale Alluvial Diamond mines are private family …

Transported by rivers and streams, these diamond crystals end up in river gravel beds and silt often at great distances from their original source. Until the late 1800s, the world's diamonds were found and collected from these alluvial beds. Today, most diamonds are found in kimberlite pipes, which are the primary source of mined diamonds.

Alluvial diamonds were discovered in 1859 in South Africa and in 1869 mining of the hard rock sources of diamonds started at Kimberley, the capital of the Northern Cape Province of South Africa. The biggest and most precious diamond ever found was discovered in 1905 by Frederick Wells, Manager of the Premier Diamond …

While minor diamond discoveries were made among alluvial gold in New South Wales starting in 1851, a discovery in 1979 on the Kimberley Plateau of Western Australia enabled the country to be the world's most prolific diamond producer. Based on ancient bedrock, diamond exploration began in 1972, with a kimberlite pipe discovery coming in 1976 in ...

Between 1866 and 1869, the first South African diamonds were discovered along the Vaal and Orange River beds (known as "alluvial" diamonds). This was …

Despite the importance of alluvial diamonds produced with respect to total diamond production in terms of their values, the alluvial deposits themselves have little to teach …

It demonstrated that this alluvial field is overall a low-volume, small-diamond and uneconomic placer, with higher diamond concentrations in localised areas. The low potential is attributed to the limited availability of diamonds from secondary detrital sources, coupled with the inefficiency of fluvial mechanisms to promote diamond concentration.