Blog – Dandenong Gem Club

Quick Guide to Precious Metal Polishing Compounds

May 19, 2018May 19, 2018
by Aden Green

Doc2 Doc3Quick guide to precious metal Polishing Compounds

Dialux polishing compound blocks come individually packaged in colour-coded cardboard boxes. The information on the boxes is in French so this table should help.

Type	Box Colour	Application Blue, White, Gray, Red, Orange, Black and Green do not contain silica
Blanc	White	Bright polishing of silver
Bleu	Blue	All-purpose compound for all types of metal
Gris	Gray	Fine polishing of stainless steel
Jaune	Yellow	For bright high polish of soft metals such as brass, bronze and copper. This compound contains silica – use PPE respirator
Noir	Black	For final polishing of silver
Rouge	Red	The brightest shine for yellow gold. Also produces a brilliant shine on silver
Vert	Green	Recommended for bright polishing of hard alloys such as platinum, white gold, chrome, chrome cobalt and stainless steel
Vornex	Orange	Pre-polish cutting compound for all ferrous metals

Other Brands of Polishing Compounds

Fabulustre Produces a fast, mirror-bright, final finish on all types of precious and decorative metals. Unlike Dialux, Fabulustre is greaseless, dry but not dusty, which means fast and easy cleanup with little or no residue. Not commonly available and is more expensive than Dialux
Luxor is another French company that makes a range of polishing mops and polishing compounds. Of particular note is the Luxor Orange polishing compound (sometimes referred to as Luxor Gold) which produces a superior finish on all precious metals. It is the best secret weapon for a mirror finish on silver. Don’t believe me?: Try it for yourself. You’ll be glad you did

Industrial and general purpose Metal Polishing Compounds

For information on other brands of polishing compounds that are used to polish non-precious metals such as aluminium and steel, please refer to the manufacturer’s guides.

At the show

Berwick Show 2018

February 24, 2018
by DLC

Here we are at the Berwick Show with our stall. Plenty to see and do with a fantastic family environment.

Everyone is loving our displays, with the show bags and lucky dip being a hit with the younger rock hounds.

Come and say hi. We are in shed 3 wedged between the sheep and the alpacas.

Silversmithing and Jewellery Making

The Berwick Show

February 10, 2018February 12, 2018
by DLC

The Berwick Show Society has a long and proud association with agricultural competition in Victoria, tracing its history back through the Mornington Farmers Society to the founding body in Victoria, the Port Phillip Farmers Society which was established in 1848.

This years show is on Saturday 24th & Sunday 25th February at the Berwick Showgrounds.

Dandenong Gem Club will be here again this year with a selection of gemstones, fossils and minerals for sale at very reasonable prices. At the show we will have free children’s activities for our junior rock hounds.

Come see us at the show!

Silversmithing and Jewellery Making

Caveat Emptor – Let the buyer beware

February 9, 2018February 11, 2018
by DLC

When it comes to purchasing gemstones over the internet, the saying“CAVEAT EMPTOR” = Let the buyer beware, should always be born in mind. Over the last few months I have made purchases and “won” several auctions on one particular internet auction site. Out of the first 5 purchases, I’m sad to say that only 1 was just as the internet seller had described.

Silversmithing and Jewellery Making

Mohs’ scale of hardness

February 9, 2018February 11, 2018
by DLC

Mohs’ scale of hardness was invented over 200 years ago as a pretty simple way of describing the toughness of rocks, minerals and gemstones. The German Geologist Freidrich Mohs devised the system based on the ability of harder stones to scratch softer ones. This means that it tests the abrasive resistance against other materials. Because of the scratches that are made, this testing process is deemed to be destructive in that, by definition, the weaker stone is damaged. For this reason, Mohs’ scale of hardness is only really useful for field testing or testing of rough, uncut and unpolished material. The higher the number the harder the material: The softest material on the scale is Talc at number one and proceeds through to the toughest, Diamond at number 10.

Knowing the Mohs’ hardness of a material can help with deciding how best to incorporate it into jewellery. For example; stones that are soft will rapidly show signs of wear if they are placed into rings that are worn on a daily basis. If we bear in mind that a common constituent of household dust is small particles of quartz sand. Quartz has a Mohs’ scale of 7 so stones with a hardness of less than 7 will show more signs of wear than stones that are harder than 7. So knowing a stone’s hardness can prove useful, and fortunately the majority of books that tell us about gemstones include in their description the stones’ hardness.

The classic list of for Moh’s scale of hardness lists the following stones:

Talc
Gypsum (Fingernail 2 – 2.5)
Calcite (Copper 3)
Fluorite (Nail 4)
Apatite (Knife blade 5 -6.5)
Orthoclase (Feldspars eg Moonstone, Sunstone and Labradorite)
Quartz
Topaz
Corundum (Ruby and Sapphire)
Diamond

Unfortunately the difference in hardness between each of the numbers is not the same. For example the difference in hardness between Calcite and Fluorite (3 and 4 on the scale) is approximately 25% whereas Diamond is approximately 300% harder than Ruby or Sapphire.

So how can we easily remember the names of the rocks on Mohs’ Scale? The following Mnemonic might be helpful: The Gem Club From Adelaide Often Queues To Cut Diamond