Showing category "Lapidary" (Show all posts)

TRIALS AND TRIBULATIONS WITH CUT GEMSTONE HEATING

Posted by Site Moderator Webmaster on Thursday, March 25, 2021, In : Lapidary

Duncan Miller

Inspired by the dramatic change in colour of the large tourmaline illustrated in last month’s Mineralogical Chatter, that went from autumn brown to a purplish-pink on heating by the client for whom I had cut it, I decided to experiment myself. A friend lent me a small ‘enamelling’ kiln; I bought a suitable crucible from jewellers’ supplier Lipman & Son in Cape Town (https://lipmanson.co.za/); and Ian Lipman generously gave me jewellery casting investment powder to protect...

PLAYING WITH QUARTZ SPHERES IN POLARISED LIGHT

Posted by Site Moderator Webmaster on Monday, August 24, 2020, In : Lapidary

Duncan Miller

It’s play time! For this exercise you need a flat computer screen with an open blank Word page, a smallish clear quartz crystal, a quartz sphere if you have one, or if not, some clear quartz beads (glass beads won't work), plus a pair of cinema 3D glasses or Polaroid sunglasses.

Quartz crystals are anisotropic. This means that a ray of light travelling through the crystal is split into two polarised rays, vibrating at right angles to each other. There is only one directio...

FABERGE’S BIRDS

Posted by Site Moderator Webmaster on Monday, July 27, 2020, In : Lapidary

Lesley Andrews

Peter Carl Fabergé was born in St Petersburg in 1846, and eventually became Goldsmith to the Imperial Court of Russia, and a supplier of wonderful artworks worldwide. He assumed charge of the workshop his father had established in St Petersburg when he was only twenty-four years old, and presented the first Imperial Easter Egg to the Russian royal family in 1884. The workshop survived until 1918, by which time Russia had succumbed to revolution and the royal family was no mor...

COVID-19 eclipses the Amazonite clouds

Posted by Site Moderator Webmaster on Sunday, May 24, 2020, In : Lapidary

by Jay and JD Haasbroek

I know for sure it was last year some time, but that’s about all I am prepared to admit to any sense of time or space in these times.

As was usual back then Verna Jooste was visiting round the kitchen table with me, and Jay was busy with stones in her adjacent cutting studio and joining the conversation every so often, with a stone in her hand. Verna, a teaching jeweller and artist, is always interested in the stone in the hand. She comes from a family of diamond c...

Southern African Lapidary Stones to watch out for: Botswana Agates

Posted by Site Moderator Webmaster on Tuesday, June 25, 2019, In : Lapidary

Willie Visser has had this Botswana agate for a number of years. Recently he decided it was time that he took the plunge to cut it, and he was amazed to find it was the most beautiful agate he had ever owned. He has called it “The Mona Visa”.

By coincidence it is exactly 10 years since he cut open another special agate and found a fish.

Two beached whales were spotted at Yzerfontein this past month, the first on 5th November and the second a few days later

Posted by Site Moderator Webmaster on Friday, November 23, 2018, In : Lapidary

And last week this fish appeared at Milnerton Lagoon

Grey chalcedony and aragonite fish

This is the same fish as above, but much prettier “when still alive”, and seen under short wave UV light.

Southern African Lapidary Stones to watch out for

Posted by Site Moderator Webmaster on Tuesday, September 25, 2018, In : Lapidary

Verdite

Verdite is a fairly soft South African stone found in the Barberton area. It is often seen in African curio shops carved into animals. Its golden flecks distinguish it from buddstone which is a much harder metamorphosed chert. Even more distinctive is the “leopard rock” which is spotted serpentinite, also from that area. JW

Buddstone

Leopard rock

Southern African Lapidary Stones to watch out for:

Posted by Site Moderator Webmaster on Wednesday, July 25, 2018, In : Lapidary

SODALITE – this is generally sourced from Swartbooisdrif, near the Kunene River in north-west Namibia. It has a Mohs hardness of between 5,5–6, is generally fine grained, and works very well.

Who Knows Nigel?

Posted by Site Moderator Webmaster on Sunday, October 23, 2016, In : Lapidary

Not many people in our club know Nigel Brown, but behind the scenes he must be one of our most productive lapidaries, in and among all his other commitments. His website has been listed in this newsletter’s advertisements for several months now (nigelbrownjadecarver.com). When I looked at it again recently I saw he had been busy producing jade kiwis so I asked him for an update of his work. He sent us this:

“Little Spotted Kiwi

This little...

THE SECRET OF A GOOD POLISH – IS A GOOD PRE-POLISH

Posted by Site Moderator Webmaster on Sunday, August 28, 2016, In : Lapidary

In the bad old days, one cut facets on a 600 mesh lap, followed by a 1200 mesh lap and then went on to polish. The 1200 mesh leaves quite deep scratches, and on some material produces ‘orange peel’, a mottled surface with alternating rough and smooth patches. This makes polishing tedious. A pre-polishing step, with 3000 mesh or 8000 mesh diamond gets rid of the scratches and any orange peel. You might think the additional step adds time to the process, but in practice it speeds it up beca...

The Romance of the Stone

Posted by Site Moderator Webmaster on Friday, May 22, 2015, In : Lapidary

“The Romance of the Stone?!”

- excitement at having found a special piece of rough that asks for faceting

- carefulness to get the right design for the rough

- caution by previewing the new design on GemCad first

- fear to start new designs or try different types of stones

- bravery to just do it

- patience to remove the initial surplus rough and reach the centre point and s...

Sing in the New Year

Posted by Site Moderator Webmaster on Monday, February 23, 2015, In : Lapidary

André Bergh gave a talk and demonstration of what were described in the last newsletter as “quartz singing bowls”. But as things turned out, the bowls were made of frosted glass, in China. There was a selection in various sizes, and they are tuned to musical notes. When tapped with a drumstick, or using one in a stirring motion rubbing against...

The Tigers Leave for the Jungle

Posted by Site Moderator Webmaster on Monday, September 23, 2013, In : Lapidary

Do you remember the Hout Bay tigers mentioned in our July newsletter? They are now finally free of their Namibian “African Dream” granite and leave for the “jungle” this week after seven months of dedicated work by Robin Kutiniyu. Each block originally weighed about 5 tons, and now is about 2,5 tons. The tigers’ bodies were worked to a high polish, and their stripes etched in freehand afterwards, with tigers eye cabochons inserted in their faces to help them see. Their bases will be...

Hunting for Tigers in Hout Bay

Posted by Site Moderator Webmaster on Monday, June 24, 2013, In : Lapidary

Who would have thought there were tigers lurking in Hout Bay?

In amongst the warehouses of Mariners Wharf, surrounded by chunks of picture stone, granite, rose quartz, sodalite and ironstone, and with an all pervading smell of oily fish, you will find Robin and his tigers. This is a stone carver extraordinaire who brings an amazing sense of movement and reality to his work. His current project of life-size tigers creeping through the undergrowth is his biggest challenge to date.

I was first int...

Fundamentals of Lapidary, Part 1, Introduction by Donald Clark

Posted by Site Moderator Webmaster on Saturday, June 1, 2013, In : Lapidary

From the International Gem Society Reference Library

Introduction
... Lapidary is a hobby that is enjoyed by people of all ages and circumstances. Unlike most hobbies, what you produce is actually worth more than the labour you put into it. For many cutters, their hobby becomes a part time, or full time profession.
... Gem cutting can be don...

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Showing category "Lapidary" (Show all posts)

TRIALS AND TRIBULATIONS WITH CUT GEMSTONE HEATING

PLAYING WITH QUARTZ SPHERES IN POLARISED LIGHT

FABERGE’S BIRDS

COVID-19 eclipses the Amazonite clouds

Southern African Lapidary Stones to watch out for: Botswana Agates

Two beached whales were spotted at Yzerfontein this past month, the first on 5th November and the second a few days later

Southern African Lapidary Stones to watch out for

Southern African Lapidary Stones to watch out for:

Who Knows Nigel?

“Little Spotted Kiwi

THE SECRET OF A GOOD POLISH – IS A GOOD PRE-POLISH

The Romance of the Stone

Sing in the New Year

The Tigers Leave for the Jungle

Hunting for Tigers in Hout Bay

Fundamentals of Lapidary, Part 1, Introduction by Donald Clark

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