Blue kookaburra's where do they come from?

I have several 2 oz en 1 oz blue/purple colored kookaburra's; they are very nice; even more beautiful then the 'normal' kookaburra's.

But i can't find anything about these special blue kookaburra's on the internet; where they come from; why they are made; how much are made and further on..

Can anyone help me with information about these coins; i would be very greatful..

Thanx Haakma -The Netherlands

 

you have a photo?

 

They are Oxygen Kooks
Source Coinweb:
The effect is created by heating (roasting) the coin in an oxygen-rich enclosure. The oxygen reacts with the surface of the coin to create a variable depth layer of silver oxide (AgO). When light strikes this translucent layer, it penetrates to differing depths before refracting, depending on the amount of silver oxide laid down.

The varying depth of the silver oxide layer across a single coin is achieved by two factors working together - stress and heat. The more that the silver has been stressed, for example in the frosted field of specimen bullion coins, the more that the surface of the silver will oxidize. Uneven heating causes oxidation to proceed at differing rates across the coin, producing a patina with colour gradations.

 

So is it a good thing or a bad thing?

 

I use to have some older Kooks that has some natural rainbow tones. They looked quite nice.
Never seen a manufactured one before so I can't comment.

 

oxygen

widely happened in numis field, few happened in round 50 cent.

edit:spelling

 

I have 6 2 oz different years and one 1oz but no 1/2 oz; They look like they're professionally made; what are they worth, you think?

 

Numismatically, anything done purposely to the finish of the coin after it comes from the mint ...is a bad thing.

But, they are still 2 oz of silver each... so you still have that silver value in each of them.

 

are they still .999 with the additional O contamination?

 

Looking at his picture, thats only surface level...there are still 2 oz of 999 pure silver in that coin.

As a matter of fact, he could use the aluminum foil/baking soda/salt/water silver cleaning method ...and they would come out looking brand new.

No scrubbing/scratching involved, and you can see the finish on the surface of the coin is nice underneath.....it would stay nice using this method.

 

i will post mine later, "gold" round 50 cent

 

If it was an 1895 coin maybe, but that coin is just a baby...nothing natural about that toning.

As easy as it it to remove safely with the aluminum foil/baking soda/salt/water silver cleaning method, it's just as easy to add with this method...


[youtube]http://www.youtube.com/watch?v=VrA7Jyw1uOs[/youtube]

 

i don't think this is natural therefore the coin is too colored; they're really more magnificant in reality;

the back side is totally clean and in hte original silver color; i don't believe these coins are from an experiment; i have them from three different country's; and they are too good made (no flaws no mistakes) for an amateur.

found another picture on the net of these coins see how beautifull they are.

 

i didnt know the guy from saw made chemistry videos

 

They look pretty nice, you shouldn't have to drop the price to sell them, nor should you need to clean them, though I am sure this is possible. There are quite a few people looking for a bit of variety and this would be a pretty original way off getting that. I have a few enamelled coins, they look pretty nice but they are usually made into broaches or pendants, the 1oz look a little large for that!

 

I am almost 100% sure these coins are the "Oxygen Coins"

The following 'Oxygen Coin' examples have been seen -

1991 1oz Kookaburra Near Tree Trunk.
1994 1oz Two Kookaburras.
1998 2oz Kookaburra on Fence.
2000 1oz Kookaburra on Branch.
2000 1oz Lunar Dragon.
2002 2oz Kookaburra over Map.
2003 1oz Kookaburra on Branch.
2003 2oz Kookaburra on Branch

 

just bought two nice blue kookaburra coins on ebay 1 ounces 1996 and 1997; just luck for 67 euro total.

http://www.ebay.nl/itm/250948371374?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649


Now i have from the 1 oz: year 1996, 1997 and 2003 and from the 2 oz: year 1994, 1997, 1998, 2000(2x), 2004.