Author Topic: 【F】《The Shenyang Mint the early coins minted above the traces》investigatory  (Read 7404 times)

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Offline RAREMEDAL

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《关于沈阳造币厂早期铸造的新中国银币上面的“扫痕”的研究探讨》
细微的扫痕,不是后来的收藏者擦拭磨损形成的,
而是当年造币厂铸造时就已经形成的,迎着光侧着看会明显些。
其呈现细密性和同向性。这种情况在沈阳造币厂早期小规格币章上较常见,上海造币厂的一些大小规格银币章上面也有类似状况。
我认为这种状况是造币厂在擦拭或打磨铸币模具时造成的。
for example:











另外,上海造币厂早期铸造的金银币,表面呈现放射形压铸闪光纹的情况常见些,在上海造币厂的内部资料中有提到,这种状况是造币厂希望尽量避免的。但这样的放射形压铸纹,对收藏者来说是重要的,我个人很看重它,也研究它,觉得它是美丽的。这种情况不同于以上的“扫痕”,这种放射纹更多的是由于金属承受强大的压力后,中心压力略大,使金属在强压下产生瞬间延展而产生的。
« Last Edit: September 23, 2012, 12:22:10 PM by RAREMEDAL »
RAREMEDAL — Feng Jingjing sir. I come from He'nan of China.
I love chinese rare medals and golden and silver coins.
My E-mail:2209925761@qq.com
My blog:  http://blog.sina.com.cn/zhongyuanfeng555

Offline fwang2450

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Good post. I believe most MCC collectors have noticed them, but few have been able to pin down the cause.

low

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Die striation line?

Underbidder

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Thank you for posting the photos-

Thanks too to Poconopenn who was recently once again very helpful explaining this not- uncommon occurance.

Further explanation would be very interesting and welcomed.

Offline poconopenn

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The coin underbidder mentioned is 1986 peace 100 yuan gold coin.

http://www.ebay.com/itm/1986-China-Gold-Year-of-Peace-100-Yuan-NGC-PF-68-Ultra-Cameo-/120983022174?_trksid=p2047675.l2557&ssPageName=STRK:MEWNX:IT&nma=true&si=FZUM0HTfWUpMTRBgQDPKsxQZKrI%3D&orig_cvip=true&rt=nc

It has the same scratch pattern as mentioned by Mr. Feng. I believe that NGC has recognized the scratches as die originated and graded this coin as high as PF68.
« Last Edit: September 23, 2012, 03:46:53 PM by poconopenn »

Underbidder

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Die striation line?


Seem more like Planchet Striation lines. Die Striations result in raised lines, these lines shown appear as scratches. Increased magnification would be helpful.

http://www.ikegroup.info/?page_id=207

Still, a deep mystery- why do they exist?  On what percentage of which coins?
What is their cause?


Underbidder

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《关于沈阳造币厂早期铸造的新中国银币上面的“扫痕”的研究探讨》
细微的扫痕,不是后来的收藏者擦拭磨损形成的,
而是当年造币厂铸造时就已经形成的,迎着光侧着看会明显些。
其呈现细密性和同向性。这种情况在沈阳造币厂早期小规格币章上较常见,上海造币厂的一些大小规格银币章上面也有类似状况。
我认为这种状况是造币厂在擦拭或打磨铸币模具时造成

So is it to be translated then planchets were scratched by wiping pre-strike to perhaps remove mold?
Then if so, comparing individual coins should reveal subtle difference in line patterns on each coin? Has this been observed?

Offline poconopenn

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So is it to be translated then planchets were scratched by wiping pre-strike to perhaps remove mold?
Then if so, comparing individual coins should reveal subtle difference in line patterns on each coin? Has this been observed?

Correction:

My answer to your question previously, as given below, may not be correct.

"Yes, this peace gold coin is known to have hairlines which cover the whole surface on both sides of the coin and are indigenous to the planchet surface."

The correct answer will be "indigenous to the die surface."

The hairline scratches cover only the mirror surface, not frost area which is high spots. This suggest the cause of those scratches are not indigenous to the planchet surface or polished post-strike. The pattern of scratches in eBay listing is identical to another coin I have examined.

Sorry for my mistake.

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Poconopenn-

If the scratches are on the die, then all coins should have identical lines. It should be easy to test, by observing a few of each coin. The difficulty arises since these coins are very scarce.

If these scratches are on the dies, it would suggest dies were roughly handled and wiped as a matter of course.
If the scratches were on the planchets, it would suggest planchets had storage issues.

To make final analysis, several coins of each type need to be compared to determine if scratch pattern is identical or different.

Offline Panda Halves

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An English Translation:
Concerning the (Striation Lines) on the surface of coins from the the early Shenyang mint.
These thin (Striation Lines) are not the result of post-mint mishandling by collectors.
Actually these lines are the result of the minting process in the early years, if you (tilt these coins in the light) you can clearly see them.
These thin lines are all close together and unidirectional.
In the early stages of the Shenyang Mint this phenomenon was quite commonplace for low mintage coins and medals, common and rare silver coins and medals from the Shanghai Mint also exhibit similar characteristics.
I believe these (die state) conditions were created when the Mints cleaned and polished their dies.

Offline SANDAC

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These striation lines are quite common in the Historical Figures series.  I have PF69 coins with such striation lines.

The attached photo is the 1992 Wang ZhaoJun which not only has the striation lines, but also have series of concentric lines from the edge of the coin to the center (from her robe to the lute).  It is difficult to photograph, but very easy to see under a microscope.  This particular coin is not graded, yet.  A PF68 graded Wang ZhaoJun has the same concentric lines, but the striation lines are at a different angle.  So these two coins were not produced by the same die.

Offline SANDAC

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It is hard to see these concentric circles on the Forum photo, so I annotated the picture with green lines and posting it here.

Underbidder

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Thanks Halves and SANDAC !  Really fascinating - these two varieties of lines then are completely different in effect and cause.

The only way that explains it, is if these are scratches on raised surfaces. Otherwise there would be contour distortions?

So the fine lines must be scratches from wiping a die, whereas the bolder concentric lines SANDAC shows must have been made on the hub, before the preparation of the die?

Offline poconopenn

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China Mint changed its die design and treatement after 1995. All pre-1995 coins had flatted mirror area as low spot and frost area as high spot and fur on panda's legs was flatted mirror surface. After 1995, all pandas had mirror three dimensional detailed fur on the legs and they were no longer flatted low spot.

The low spot (mirror suface) in the coin is the high spot of the production die. I believed that Mint in ealier years might try to wip clear the die surface and caused the hairlines, mostly on the flatted high spot of the prodcution die, therefore, many hairlines on the mirror surface of the coin, and less visible on the frost surface.

1986 peace gold coin has a very low mintage (960), the number of production die would be one or two. The chance would be good that the die cleaning might be done during the middle of the prodcution, not at the start of the production. Since NGC graded eBay listed coin as PF68, NGC had to see many of this surface defected coin in the past.  

Underbidder

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Yes, exactly my thinking too.

Offline Panda Halves

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Poconopenn,
This minting description makes sense with some of the articles I have read recently.
Concerning the way older pandas were minted I came across some interesting vocabulary.
"以凹作凸"
I translated it as the use of the "Concave to Convey Convex."
Does that make sense?

Offline poconopenn

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Poconopenn,
This minting description makes sense with some of the articles I have read recently.
Concerning the way older pandas were minted I came across some interesting vocabulary.
"以凹作凸"
I translated it as the use of the "Concave to Convey Convex."
Does that make sense?

Yes, the production die is the negative impression of the coin.

Offline NBM

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Upload of missing pictures from OP found here: http://71ee.bqcoin.com/read-htm-tid-1798.html