North Brisbane Lapidary Club

We Dig Rocks

Family Bracelet

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Family Bracelet

by Mary Lancaster

  • Cut heart shape from silver plate. File and smooth edges. Punch a hole on each side.
  • Cut length of round wire (gold or silver), form heart and sweat solder onto heart plate.
  • Select decorative stamp eg. dragonfly, stamp onto silver heart.
  • Stamp letters onto heart, each one for a family member.
  • Make links for bracelets:
    • 11 x 8.5mm jump rings, pulled long (1mm, ½ round)
    • 11 x 3.0 mm jump rings (joiners)
    • 1 x 2.5mm jump ring (to attach clasp)
  • Solder links together and attach to heart plate. Attach clasp. Clean solder joins. Polish.

Live Love Bracelet

by Mary Lancaster

  • Cut length of silver plate, shape and smooth (file, emery paper). Punch hole each end.
  • Stamp chosen words, symbols.
  • Make bracelet:
    • 10x 8.5mm jump rings, pulled long (1mm, ½ round)
    • 10 x 3.0mm jump rings (joiners)
    • 10 x 2.5mm jump ring (to attach clasp)
  • Solder links together and attach to heart plate.
  • Attach clasp.
  • Make small wire heart (silver or gold). Attach with small jump ring.
  • Clean solder joins. Polish.

Broom Casting and adding patina

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by Fiona Watts

A lot of us have done broom casting at the club and I for one had a lot of fun. It’s so addictive, I think we have all done quite a few ‘pours’ and most of us have gotten some really good results. But what can you make from the end results?

I’ve made a couple of pendants (how many can one person wear though right!?!?), some earrings and STILL have some great looking broom castings left over.

The photo is of the same pendant, just showing different sides…..

So I thought about what else I could make and one piece really lent itself to a ring.

First I made a plain, simple ring shank or band. Then annealed the casting piece. And VERY CAREFULLY bent it little by little into a crescent shape. Carefully, as I didn’t want to mar the silver or damage the design. Annealed several times while bending.

Once it was kind of the shape and size I wanted, I made the ring shank the same shape as the casting using pliers. Like matching a bezel to a stone.

Then much to Carol M’s dismay, used a small butane torch to solder it together. She didn’t believe I could solder such a ‘large’ piece of silver with a small torch.

Success!

It’s kind of all about confidence and experience I guess.

Sorry I forgot to take progress shots.

As most of you know, I’m a patina girl. Love, love, love patinas.

And look what groovy colours I got!

Keep creating. And smiling.

Fiona

Do you know Mohs?

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by Katarina

Mohs – Carl Friedrich Christian – was an old German fella, a geologist and mineralogist. He lived some time ago (1773 – 1839). You wonder why I mention Mohs? Well, he expanded on the knowledge from Theophrastus and Pliny the Elder who determined that Diamonds where pretty hard compared with other minerals such as Quartz.

Good old Carl used the knowledge from those who came before him and it became the basis of the hardness scale he developed, today known as Mohs’ Scale of (Mineral) Hardness.

When Mohs developed his hardness scale in 1812, very little information about mineral hardness was available. He simply selected ten minerals that varied in hardness and arbitrarily placed them on an integer scale from 1 to 10. It was a relative scale in which a mineral of unknown hardness could be tested against a group of ten index minerals to see where it positioned on the scale.

You most certainly have heard talk around the club house of how hard a piece of rock / mineral / gemstone is when people want to polish them.

This hardness is actually measured by the Mohs Scale of Hardness. The scale measures the scratch resistance of minerals, how difficult it is to scratch a specific mineral. This has an impact on how difficult it is to polish one of our pieces into a beautiful cabochon or faceted stone.

The highest resistance to scratches is found on diamonds and they have been assigned the hardness 10. The least resistance to scratches is talc – it basically scratches itself – and it therefore has the hardness of 1.

The higher a mineral is on the scale, the harder it is to polish. And the reverse works of course too, the lower the ranking, the easier it is. Which of course means you could polish a low ranking mineral away to nothing in no time.

A good indicator to how hard a mineral might be is sawing a piece. The more the saw has to work, the harder it usually is.

But all in all, the scale doesn’t mean much. After all, what does it mean for example, that an Amethyst has the hardness 7 if you have nothing to compare it with? The numbers on the scale are just that, numbers.

So I have searched the net and asked my friend Google if there are any examples for the hardness. And as Google knows everything, it has delivered. The combined findings are in the table.

One of the comments that I remember is that Stones with hardness of under 4 may not polish at all or will only take a light shine. Most of the stones hobbyists polish are found in the 6 to 7 range.

As you will see in the table, many minerals don’t have a specific hardness but rather sit on a sliding scale, depending on the composition of the minerals.

And if you ever find yourself in Vienna, why not look for the memorial plaque in honour of Carl Mohs.

Sources:

https://www.gemsociety.org/article/select-gems-ordered-mohs-hardness/ – here you will find a more complete list of minerals and there hardness according to Mohs

https://geology.com/minerals/mohs-hardness-scale.shtml – more in depth information. Including how to test minerals.

https://en.wikipedia.org/wiki/Mohs_scale_of_mineral_hardness

https://www.britannica.com/science/Mohs-hardness

More homework

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by Lola

Not only has Lola been busy with her usual baking and jam making, below are some fine examples of her work in silver.

The pendant with the rings was made from recycled jewellery.

Dragons

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by Carol Money

I have been dabbling with some cloisonne and transparent colours enamelling. The earrings are made from copper, with a layer of silver foil and several blended layers of translucent enamels. Ideally a kiln would have been used to fire the pieces but having to work with what I had at home, they were torch fired.

These ear-rings were made for another of my friends that has turned 60.  We met while dragon boat paddling, hence the dragon.

I know that one of the pieces should have been facing the other way (I was sure I had worked it out but it appears not!)

Sweat Soldering

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by Ray Wilson

Sweat soldering is a simple process that can be used to create depth, texture or contrast to your work.

Solder is applied to the back of the piece that is going to be the top of the finished item. It is cleaned and positioned on the back plate and the complete piece is then reheated until the solder flows between the 2 pieces.  The surfaces of course have to be flat and free of grease.

Here’s a piece I have just completed.

Silver Loop Ring

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by Mary Lancaster

Materials

  • 1.5mm round silver wire

Steps

  • Make jump rings: 1 x 9.75 mm mandrel, 2 x 8.5 mm mandrel, 2 x 6.0 mm mandrel
  • Solder and pull into oval shape, use flat-nose pliers to level sides of ovals
  • Hammer each jump ring
  • Use file to flatten sides of jump rings ready to join
  • Solder two medium-sized jump rings to larger jump ring
  • Solder two smaller jump rings onto each side
  • Shape to form top of ring
  • Cut two approximate lengths of round silver wire to make shank of ring
  • Solder two lengths together (tie each end together with wire to hold)
  • Measure shank for correct size to form ring, file ends flat ready for soldering
  • Solder one end of shank to ring top (easier to place in hole in firebrick)
  • Gently shape shank and solder other side to ring top
  • Use ring mandrel and nylon hammer to reshape finished ring
  • Use file and emery paper to clean
  • Final clean with brass brush
  • Polish

Other rings made with ‘odds and ends’ of silver.

Grading Gemstones

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Article submitted by Marie-Ann Coyle

Gemstone Grading by Lexi, Exclusively for Fire Mountain Gems and Beads

https://www.firemountaingems.com/resources/encyclobeadia/charts/e893

There are a lot of steps to grade a gemstone. Each step of grading focuses on a different feature and has many details that create the overall grade determination. It can be difficult to understand gemstone grades without training, so with the help of the Fire Mountain Gems and Beads gemologists we’ve created a chart to help clarify the basics. Images of both emerald and lapis lazuli are shown to illustrate transparent and opaque versions of each grade. There are other factors taken into consideration when grading colored gemstones such as the quality and rarity of the material, enhancements, overall size of the stone, uniformity of shape, quality of cutting/faceting and the combination of graded features.