Stones of South Africa-Part 1

Stones of South Africa-Part 1

Sammy Chris

“The Rainbow Nation” - South Africa is one of the most ethnically diverse countries in Africa. This country is on the southernmost tip of the African continent, marked by several distinct ecosystems. 

Cape Town, the capital, is named after the Cape, the southernmost point of the African continent.

Geological landscape

Stones of South Africa

This country has numerous famous geological features, the center of the country is a semi-arid plateau surrounded by mountain ridges.

The main geological feature is of rather ancient, Precambrian origin, about 

3Ga old. The central areas are composed of Precambrian crystalline rocks, mainly Gneiss and Granite, but also Archean mafic-ultramafic volcanic sequences. Those rocks are among the oldest known rocks on Earth. There exist a few locations with much older rocks, e.g. in Iceland, but they are heavily altered and found only in very small spots. So the Precambrian rocks of South Africa are the oldest formation of rocks with a considerable size. The most interesting fact among those rocks is their structures which are created by the fast cooling of the lava which requires many different atmospheric conditions to be formed. They allow the reconstruction of the composition of the atmosphere while they were formed and thus allow a glimpse of Earth's atmosphere 3Ga ago.

Stones of South Africa

(Precambrian - South of Africa)

Many deposits originate from this era, gold-bearing conglomerates and banded iron formations. 

The gold is of great economic value and the backbone of the Kruger Rand currency, symbolized by the famous gold coins. Later millennia saw volcanism, especially the formation of the famous diamond-bearing kimberlite pipes about 1Ga ago. Kimberlite is formed under high pressure and temperature in the pipes deep inside the volcano, and during this process, the carbon in the lava is converted into a diamond. And diamonds are the second important backbone of South Africa's economy. 

The country has numerous limestone and dolomite areas suitable for karst development The total area of karst is very small in relation to the size of the country. The main karst areas are Bredasdorp in the south, Groot Swartberg, a little to the north, a huge area south of Kuruman, and Transvaal and Drakensberg. 

Most of the carbonate rocks are dolomites, often crisscrossed by igneous dykes. 

The country also has notable noncarbonate karst. There are several caves in the hard sandstones of the Cape Peninsula. At the southern end of the Drakensberg area are caves and karst features formed in quartzite. 

Dimension Stones

Dimension stones are natural stones that can be cut into specific sizes and shapes for various construction and decorative purposes. Sandstone, a dimension stone, is popular for building houseware, domestic construction such as paving, landscaping, tiling, and other artistic works.

The construction sector accounts for over 80 percent of consumption, with the funerary, monumental industry accounting for 15 percent, and various special applications for around 3 percent.

South African dimension stone production consists mainly of granitic rock with slate and sandstone making up the balance. The term “granite” is applied very loosely in the industry and is used to describe almost any medium- to coarse-grained igneous or metamorphic rock. 

While a wide variety of dimension stones has historically been used in South Africa, the current production consists of almost exclusively granite. 

Commercial production of granite has its roots in the Rustenburg area (North West Province). Exports of South African granite commenced in the 1950s and these soon became popular in the monumental market, with the result that many quarries were started in the Brits-Rustenburg area, up until the mid-1980s. 

More than thirty different colors of granite are produced, along with several quartzite, sandstone, and slate. The so-called classic material - Rustenburg Grey, Olive Green, African Red, Belfast Black, and Verde Bitterfontein – are always in demand and used extensively throughout the world in both the construction and monumental industries. 

Rustenburg Grey 

Rustenburg Granite is a black granite having a dark black base with large dark grey grains intrusive igneous rock which is granular and phaneritic in texture quarried in South Africa. This stone also is known as, Africa Impala Granite, Africa Nero Impala Granite, Africa Rustenburg, African Impala Granite, Africa Schwarz Granite, Black Impala Granite, Diorit Impala Granite, Eagle Black Granite, Gabbro Impala, Granite Impala, Impala Black Granite, Impala Gabbro, Impala Granite, Impala KM Granite, Impala Nero Granite, Impala Nero Granite, Impala Schwarz Granit, Impala-Granit, Jasberg Granite, Marciana Granite, Marikana Black Granite, Nero Rustemberg Granite, Nero Rustenburg Granite, Nero Rustenberg, Nero Sudafrica Granite, Nero Africa Granite, Nero Africa Impala Granite, Nero Afrika Granite, Nero Afrika Impala Granite, Nero Impala Granite, Nero Impala Africa Granite. 

This accounts for over 70% of South African production and is the single largest volume material traded on world export markets comprising more than 7% of world granite trade.

African Red Granite

Africa Red Granite is a kind of blazing red with an intensive red and white pattern (black spots) granite quarried in South Africa. It is also called South Africa Red Granite, African Red Granite, Red Africa Granite, Rojo Africa Granite, Africa Granite, Granite Rouge Afrique, Granito Vermelho Africa, Imperial Red Africa, South African Red. 

Stones of South Africa

(African Red Granite)

Impala Black Granite

As suggested by the name, this marvelous black granite is quarried in the northeastern province of South Africa. It is also known as Nero Impala as it is found among the ravishing landscapes with prosperous wild fauna where one can often observe grazing impalas, an African species of antelopes.

Stones of South Africa 

(Nero Impala Granite)

Belfast Black granite 

It is a fine-grained, black gabbro/norite of the Precambrian period. ... Quarry Location: Belfast Black granite is quarried near Wapadskloof, Belfast, Mpumalanga, South Africa, and this is most probably the first granite referred to as Nero Assoluto by the Italian stone industry.

Stones of South Africa

(Belfast Black Granite)

Verde Bitterfontein

Limited; which accounted for 94 percent of South African dimension stone production, from 26 quarries. This is a coarse-grained, dark green granite of the Precambrian period, the color is caused by chlorite. The veining and color variations and a small sample of Verde Bitterfontein granite may not be representative of the whole slab therefore swatch samples must be approved for large projects to ensure that the blocks are all extracted from the same quarry face for matching purposes. 

African dimensional stone industry was dominated by three companies, Marlin Holdings Limited, Kelgran Limited, and R.E.D. Granite 


Read More - Stones of South Africa-Part 2

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