WITWATERSRAND
GEM and MINERAL CLUB
Newsletter - June 2016
P O Box 3708 Cresta 2118 South Africa
Room 215, 2 floor Department of Geology University of Johannesburg Auckland Park
nd
JUST A WORD FROM THE EDITOR
June is FOSAGAMS Vivo time. The closing date for booking and deposits are
on Friday, June 24 2016. So get to it and book your spot.
The position of FOSAGAMS Editor is still available. Please contact Linda
Stone should you be interested (082 598 9117/ [email protected]).
This month’s theme evening will focus on Cuprite minerals from all over the
world, as well as Dioptase from African localities. Join us at the month end
meeting where Graeme Hoffman will share his passion for making spheres
in his talk on “From Boulder to Beautiful”.
Pretty Rocks –
American Museum of Natural History
Welcome to Karl Gribnitz (Secunda) and Michael Wendler (Tucson, Arizona) who both joined Wits Gem &
Mineral Club in May 2016.
EVENT CALENDAR
THEMED EVENING : 8th June 2016 (please bring three specimens of each theme below) –
1) Cuprite Worldwide
2) Dioptase – African localities
SPEAKER EVENING : 29th June 2016 – Graeme Hoffman will present a talk “From Boulder To Beautiful”
FOSAGAMS Vivo Outing 2016 – Wednesday 29 June until Sunday 3 July 2016
FOSAGAMS Groot Marico 2016 : due to the GEMBOREE being in such close proximity, FOSAGAMS advised that this
annual event will only take place in the last quarter of the year after the VIVO trip
27 August - 4 September 2016 : 35th International Geological Congress, Cape Town
Rock Science OPEN DAY – October 2016 (date to be confirmed)
WGMC Year-end evening: 30th November 2016 (members only)
GEMBOREE 2017: The 50th Gemboree will be held over the Easter Weekend, 14-17 April 2017
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THEMED EVENING
(1)
Cuprite Worldwide
Named in 1845 by Wilhelm Karl von Haidinger from the Latin "cuprum," in allusion
to its composition. Haidinger renamed a previously known mineral that had been
known by a wide variety of names. Cuprite is commonly found as an oxidation
product of copper sulphides in the upper zones of veins, often associated with
Native Copper, Malachite, Azurite, Limonite and Chalcocite. A fibrous form of
Cuprite is known as Chalcotrichite. (http://www.mindat.org/min-1172.html)
SCIENTIFIC: Cuprite is a copper oxide mineral found as octahedral, cubic or dodecahedral crystals formed in oxidized
zones of copper deposits. The presence of Cuprite is often found in copper rich areas along with deposits of
Chrysocolla, Malachite, Limonite, and Azurite. Cuprite colour ranges from bright crimson red to brownish or blackish
hues depending on the formation and impurities in the area. Cuprite is translucent to semi-opaque with an
adamantine to dull lustre. Cuprite’s hardness is rated 3.5 to 4 on the Moth’s scale of mineral hardness. The name
Cuprite comes from the Latin word cuprum meaning “copper.” Cuprite is found worldwide.
(http://www.ravencrystals.com/CUPRITE_df_1160.html)
Cuprite has been a major ore of copper and is still mined in many places around the world. Of all the copper ores
except for native copper, cuprite gives the greatest yield of copper per molecule since there is only one oxygen atom
to every two copper atoms. As a mineral specimen, cuprite shows fine examples of well-developed cubic crystal
forms. Cuprite's dark crystals show internal reflections of the true deep red inside the almost black crystal. Other
varieties, such as chalcotrichite, show tufts of needle-like crystals that have a beautiful red colour and a special
sparkle that make them popular display cabinet specimens.
PHYSICAL CHARACTERISTICS:
 Color is red to a deep red that can appear almost black.
 Luster is adamantine or submetallic to dull or earthy if massive.
 Transparency: Crystals are transparent to translucent.
 Crystal System is isometric; once thought to be 4 3 2 but now believed to belong to 4/m bar 3 2/m.
 Crystal Habits include the cube, octahedron, dodecahedron, and combinations of these forms. Some display
faces of the obscure gyroid form. A variety known as Chalcotrichite forms long needle-like crystals or fuzzy
crusts. also massive.
 Cleavage is fair in four directions forming octahedrons.
 Fracture is conchoidal.
 Hardness is 3.5-4
 Specific Gravity is approximately 6.0 (very heavy for translucent minerals)
 Streak is brick red.
 Associated Minerals are limonite, copper, chrysocolla, malachite and other secondary copper minerals.
 Other Characteristics: Forms a surface film with long exposure to strong light. Crystals of cuprite are
sometimes altered or partially altered to malachite and rarely copper.
 Notable Occurrences include Arizona, USA; Africa; Australia; Chile and several localities in Europe.
 Best Field Indicators are color, crystal form and softness.
http://www.galleries.com/cuprite
READ MORE:
 http://www.minerals.net/mineral/cuprite.aspx
 http://www.handbookofmineralogy.org/pdfs/cuprite.pdf
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(2)
Dioptase – African Localities
The name dioptase comes from the Greek language. Dia- "through" and optomal- "vision".
Dioptase is an uncommon mineral found mostly in desert regions where it
forms as a secondary mineral in the oxidized zone of copper sulfide mineral
deposits. However, the process of its formation is not simple, the oxidation of
copper sulfides should be insufficient to crystallize dioptase as silica is
normally minutely soluble in water except at highly alkaline pH. The oxidation
of sulfides will generate highly acidic fluids rich in sulfuric acid that should
suppress silica solubility. However, in dry climates and with enough time, especially in areas of a
mineral deposit where acids are buffered by carbonate, minute quantities of silica may react with
dissolved copper forming dioptase and chrysocolla.
The finest specimens of all were found at the Tsumeb Mine in Tsumeb, Namibia. Tsumeb dioptase is
wonderfully lustrous and transparent, with its crystal often perched on an attractive snow-white
carbonate matrix (https://en.wikipedia.org/wiki/Dioptase).
One thing many people may not know is that a dioptase
gemstone should never be exposed to ultrasonic cleaning or
the fragile gem will shatter.
Mineral Facts:
 Chemical Formula: CuSiO2(OH)2
 The mineral is a hydrated metasilicate
 Colors are Emerald-green or blackish green color,
and a green streak
 Hardness : 5
 Density: 3.2 to 3.35
 Cleavage: Rhombohedral, perfect three directional cleavage
 Crystallography: Rhombohedral. Its crystals are columnar. Besides occurring as crystals the
mineral is found also massive and in crystalline aggregates
 Luster: Vitreous, transparent to translucent
 Used: As a ground pigment, Dioptase can be used to make paint
READ MORE:

http://www.minerals.net/mineral/dioptase.aspx

http://dioptasewebsite.weebly.com/

http://nevada-outback-gems.com/mineral_information/dioptase_mineral_info.htm
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SPEAKER EVENING
FROM BOULDER TO BEAUTIFUL - The making of spheres
Join the WGMC on Wednesday, 29th June 2016 for a talk presented by
one of our members, Graeme Hoffman, on the making and collecting of
spheres.
After Graeme completed his National Service he joined Falconbridge
Explorations and worked as a Geological assistant for a couple of years,
doing air survey and sampling work, then went on to study Production
management and become a Founder Fellow of the PMISA.
After ten years of work as a production and factory manager he started
his own business in the green
industry, two years later his wife joined him, and next year (2017) the business
will be 30 years old.
Graeme’s first memory of his interest in minerals and stones was at the age of
about 5 when he found a mudstone with some crystals in a small vug. He has
collected rocks and minerals on and off since then, getting involved with exotic
bird breeding for about 20 years, but for the last 8 years he has only collected
mineral specimens and spheres.
Graeme is married with two daughters.
Orpiment Jasper Sphere
Graeme’s talk is titled “From Boulder to Beautiful”, and is a discussion on why
he chose to make spheres and how we do it.
SPEAKERS FOR 2017
Whilst 2016 is moving at a steady pace, 2017 is just around the corner. You as a club member are hereby invited to
present a talk on any gem or mineral related subject. Should you be willing to present a talk, kindly advice the
secretary accordingly or your topic and preferred date to do so (dates listed below).
Alternatively, should you know of a person in this field that would be interesting to listen to, and willing to present a
talk, kindly forward their details through (name, topic, and contact information).
The dates for 2017 speaker evenings are as follows:
 25 January
 22 February
 29 March
 26 April
 31 May
 28 June
 26 July
 30 August
 27 September
 25 October
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VIVO OUTING 2016
Linda Stone has co-ordinated another trip to Vivo starting on Wednesday June 29th at 11:00, meeting at the new
garage, and will end on Sunday July 3rd. Minerals to be collected are agates, calcite, carnelians, copper related
minerals, dragonstone, garnets, green quartz, quartz, ruby corundum and unakite. You will also visit shaft 5 (The old
Messina Mine). Harry Smith’s house will also be visited to view his collection of Messina quartz and ajoite crystals.
It will be advised to wear the appropriate gear. One of the sites to be visited is an operating mine, and according to
the Mine’s Act you have to wear a hard hat, a reflective jacket as well as sturdy shoes. Please keep in mind that
snakes are commonly found in this area. The media stated that the malaria mosquito has been detected as far as
Mopani. Please take precautionary measures as well if you suffer from any medical condition.
Accommodation is available on Ari and Sannie Kruger’s farm called ‘Dankbaar’ which is situated near Alldays. You
can stay as long as you wish. The following accommodation is available (50% deposit is required, the balance to be
paid in cash on arrival):


Rooms: (The main house and the ‘jaghuis’): R 200.00 pppd with shared facilities. Children under the age of
18 free of charge. Linen and towels will be provided.
Camping and caravanning: R 75.00 pppd. Children under the age of 18 free of charge. Please remember to
bring an extension cord. Bathroom facilities will be shared.
The following facilities are available: Barbecue facilities, a fully equipped kitchen (gas stove, fridge, freezer, cutlery,
and crockery), cold store, tables and chairs. Sannie will spoil you with her homemade dishes for the evening braais
(pap and sous / potato dish).
Directions to the farm ( S 22º37.55,6 E 29º22.42,0 ): From Polokwane (Pietersburg) take the R521 to Alldays. Turn
right onto the Bronbeek Road. This road is about 1,5 km before Alldays. Be on the lookout for the 22 km and 23 km
concrete markers, turn right at a sign board indicating ‘Ari en Sannie Kruger’. Travel down this road, fenced on the
one side with game fencing for 8 km. When approaching the MTN tower the farm house will be visible. Travel time
from Pretoria to Vivo via the N1 highway is approximately 4 - 4½ hours.
Bookings: Call Sannie Kruger on 071 0487 381 to book your accommodation. Please contact Linda Stone per SMS
afterwards to confirm the booking. Provide all the names, surnames, cell numbers and booking details from you as
well as those accompanying you. You can contact her at 082 5989 117.
Ari and Sannie Kruger’s banking details:
Bank: ABSA
Account holder: A.J. Kruger
Account number: 4074272986 (cheque)
Branch: Pietersburg
Reference: Your name and surname
The closing date for booking and deposits are on Friday, June 24 2016.
CLUB MEETINGS
The club meets every second and last Wednesday of each month at 19h00 for 19h30, excluding December, at the University of
Johannesburg, Auckland Park, Department of Geology, Second Floor, C1 Room 215G. Please use the entrance off Ditton Road,
the building is directly opposite the mentioned entrance and parking is available to the left (limited) or around the turning circle
to the right (plenty available). We welcome all visitors. Tea, coffee and biscuits are available at a donation of R4.00.
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MEMBERSHIP
Club membership includes a monthly newsletter and news on the latest happenings, workshops and outings of other clubs
across the country. Further, you will be an automatic member of the Federation of Southern Africa Mineral Society
(FOSAGAMS) and receive the Lapidary Magazine three (3) times a year free of charge. As a member you are exclusively
invited to the yearly Gemboree held over the Easter Weekend, at cost (accommodation, meals, t-shirt, admin) determine by
the hosting mineral club - all rocks and minerals collected during this weekend are free of charge.
Annual membership fees until 28 February 2017, are as follows:
 Full/Family Member
R250 per year (Note: the family member has no voting right)
 Pensioner Member
R150 per year
 Students
R90 per year
Kindly pay your club fees and forward the proof of payment to [email protected] . This will enable you to continue to
participate and enjoy the club’s benefits. Should you have a friend or colleague who wishes to join the club, kindly contact the
club secretary for an application form. Fees are payable to the Treasurer, Jono Hotz. The WGMC Banking details are as follows:
Standard Bank
Cheque account
Account number:
200551744
Branch code:
006305
COMMITTEE MEMBERS
The following club members, by overall support of the members attending the meeting, have accepted to stand on the
2016 committee on the 24th February 2016:
Chairman
Massimo Leone
082 372 0328
[email protected]
Vice Chairman
Kevin Hean
083 267 5342
[email protected]
Treasurer
Jono Hotz
082 444 9628
[email protected]
Editor & Secretary
Claudette Denner
072 591 6202
[email protected]
Other Club Contacts (non-committee members)
 Raffle Master
Keith Bailie
 Mineral Section
Damian Kislig
 Librarian
Murray Skikna
 Facebook Page
Stephan Gomersal
082 928 9515
072 203 1351
076 447 7327
082 774 0746
RAFFLE
The monthly raffle takes place on the last Wednesday of every month. Raffle tickets are on sale in the meeting room on the
night at R10.00 each. Those selling minerals at the club, please donate a nice rock to the raffle. Contact Keith Bailey at the club
meetings in this regard. We are requesting all mineral and gem dealers to please donate a specimen or two for the raffle. Keith
would be happy to assist.
LIBRARY
Murray Skikna was elected on the 24th February 2016 to take over the Library from Massimo Leone. Please contact Murray on
[email protected] or 076 447 7327 to assist you to borrow books and/or magazines. Murray will update the current library
and will give assistance to members wishing to borrow books. Should you have any books (old or new) on minerals, geology or
lapidary that you wish to donate to the library, please contact our new Librarian.
SOCIAL MEDIA
WGMC is on Facebook. Please join our group to receive the latest news on our meetings and speakers.
https://www.facebook.com/Witwatersrand-Gem-and-Mineral-Club.
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LINKED SOCIETIES
We exchange newsletters with the following societies. Should you be interested in reading any of them please contact
[email protected] and I will email them onto you. If you wish to join any of the clubs, or attend their lectures and
outings, please contact the person listed below:

FOSAGAMS
Linda Stone
[email protected]

South African Micro-Mount Society
Alison Rose
[email protected]

Natal Mineral & Gem Society
Frank Farquharson [email protected]

Pietermaritzburg Gem & Mineral Club
Craig A’Bear
[email protected]

Nelspruit Gem & Mineral Club
Paul Vermaak
[email protected]

Pretoria Gem & Mineral Club
Willem Vorster
[email protected]

Cape Town Gem & Mineral Club
Malcolm Jackson [email protected]

Kimberly Lapidary Club
Ludi von Bezing
[email protected]
ADVERTS
Turn your modest display
into a master piece!!
Various Perspex Mineral stands for sale.
Please contact Jenny for brochure.
JenEric Mineral Stands
Cell: 084 810 156
E-mail: [email protected]
A selection of hand and head sized specimens
available for sale. Please contact Sharon on
082 923 4794. www.stores.ebay.com/sahotrocks
If you are a club member and you wish to advertise your
mineral or related type business, please email the editor
your details/advert layout in order to publish it in the
monthly newsletter.
DISCLAIMER
If you have received this email in error, or wish to be added/removed from our mineral related mailing list, please REPLY to
[email protected] with subscribe or unsubscribe in the subject line.
SOMETHING TO THINK ABOUT
“Every specimen has a distinctive value. It stands for time and toil. Its value increases with time. Its mission is to tell
the story and impress the lesson of creation’s plan. As a civilizer it fills a place in the life’s economy. We want more
students of the glory of the earth and the heavens.” – (from p. 73 in “Some Remarks” July 1901, v.8, n.5, p.71-73)
AT THE END
Thank you for taking the time to read through the WGMC newsletter. Remember that if you have something to add
or share with your fellow members please feel free to email the details to [email protected]. Rock on!!!
Claudette Denner
Wits Gem & Mineral Club
Newsletter Editor & Secretary
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