Zeitz Museum of Contemporary African Art

May 24, 2018
Once the grain silos of Cape Town Harbour

Built in 1923 the old silos in Cape Town Harbour were used for storing grain awaiting export, and were in operation until 1995. Today they house a modern art gallery. Thanks to the generous sponsorship of Jochen Zeitz, (former CEO of Puma) and the incredible architectural imagination of the Heatherwick Design Studio, the building is now a magnificent place to visit. The old round tubes of silo have been cut away in specific places to open up a central hall, encase lift shafts and staircases, as well as adapted to be rectangular rooms holding the artwork. The cut-away cement sections have been sculpted and polished – no doubt with a variation of the diamond pads we use in our workshop to polish our cabs and carvings! Another point of interest to us rockhounds might be the variety of stones that was used in the concrete when building the original silos.


An outside view of the silos


The main entrance hall with hanging dragon sculpture


Aggregate used in the original structure’s concrete


A view of the lower floor of the entrance hall showing how fantastic the sculpted concrete now looks
 

Faceting

May 7, 2018

Here are two stones that Duncan Miller cut recently from rough he bought two months ago at Open Day. The yellow citrine (from Johann de Jongh) has only 58 facets, is 22 mm wide and weighs 37 ct. The design is ‘Xephyr’ by Arya Akhavan (yes, with an ‘X’). The light green fluorite (rough from Rob Smith), is the first one he has ever cut. It has even fewer facets, only 36, is 15,5 mm wide and weighs 16,2 ct. The design is slightly modified from ‘Six Shooter’ by the late Jeff Graham.  ...


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Visit to Mineral Services and the Exhibition “Messengers From The Mantle”

March 29, 2018


By kind invitation of Professor John Gurney, 25 club members visited Mineral Services on 24th February to see his exceptional exhibition “Messengers from the Mantle”. This irreplaceable collection of kimberlites was initially created for the 35th International Geological Congress at the Cape Town International Convention Centre in September 2016, and was displayed again at the 11th International Kimberlite Conference in Gaborone, Botswana in Septembe...


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Field Trip to Yzerfontein

March 29, 2018
Sunday, 18th March

Pictures speak louder than words.


Brunsvigias alongside the West Coast road


24 members learning about an example of gabbro


Coastal erosion from the winter storms of 2017


An igneous breccia dyke


A 70,000 year old archaeological midden


Inspecting rocks on Schaapen Eiland


Iron pyrites


Inclusions of gabbro in the breccia dyke


Inclusions of chilled wall rock in the monzonite

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Faceting

January 17, 2018

 A magnificent 63 carat sphalerite from Aliva in Spain (http://gem-sphalerite.com/) cut by Duncan Miller. The design is Marco Voltolini’s “Superstarfish Dome 80”.

 

 A unique type of blue-green garnet has entered the gem market. The garnets reportedly come from a deposit near the border of Tanzania and Kenya. GIA’s Carlsbad laboratory obtained a small parcel of blue-green rough material and two faceted stones for examination. Unlike traditional blue-green garnets that exhibit a colo...


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“Tripping” in Namibia

November 24, 2017

The word “tripping” can have two meanings:  a tour or journey, or an unintentional slip, blunder or happening.  On this occasion both senses of the word applied. Malcolm and his friends covered a lot of ground and saw a wide variety of things when in Namibia, but not without incident.

To start off with, by the time Australian Graham landed in Cape Town, he had lost his passport, which necessitated a return to Johannesburg and the Australian Consulate for a new one. He then flew from JHB...


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Faceting

November 24, 2017

 

“Eye of the Storm” a faceting design created by Robert W. Strickland on 12th September 2017, in honour of those who suffered loss in the Caribbean hurricanes of 2017.

This design was first published in the United States Faceters’ Guild newsletter of September 2017.

When photographed directly into the centre of the culet, all the crown facets go dark, and the only light is in the “eye”, but viewed from other angles, the stone ...


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THE POLARISCOPE, THE FACETER’S FRIEND

September 23, 2017

Duncan Miller

A polariscope consists essentially of two polaroid filters, or a source of plane polarised light and one polaroid filter. The source of polarised light can be a white computer screen or even the sky, viewed at 90 degrees to the Sun. For the filter, or analyser, you can use a sheet of polaroid, or a lens from a cheap pair of 3D movie spectacles.

Let’s start with a white computer flat screen. Even an older cell phone screen without a plastic cover produces plane polarised ligh...


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9th September, 2017. The Jan Coetzee Quartz Crystal Reunion

September 23, 2017

About ten intrepid Jan Coetzee crystals made it to the reunion, with two of 50 kg-plus guys sending their apologies due to being overweight, along with a couple more whose owner couldn’t provide transport on the day. One rare and seldom seen fluorite (also from the same crystal pocket) came, and was much admired. Malcolm Jackson gave a short presentation about the mine and its location, along with photos taken by him and Jo of the Jan Coetzee mine dumps in recent years and the remains of th...


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FACETING THE NAMIBIAN RARITIES

August 24, 2017

Duncan Miller

During the 1974/75 university holidays I was fortunate to work for Sid Pieters in Windhoek for several months. It was a wonderful experience, including seeing some of the most famous mineral specimens then coming out of Tsumeb, but also to encounter some very special gem materials. Through Sid Pieters’s generosity I returned home to Cape Town with a few small fragments of jeremejevite from the original Namibian occurrence at Cape Cross and some pieces of cuprite from Onganja t...


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