It is currently Thu Mar 28, 2024 9:07 am

All times are UTC - 8 hours [ DST ]




Post new topic Reply to topic  [ 13 posts ] 
Author Message
Offline
 Post subject: Help Identifying Stones
Post #1 Posted: Thu Mar 17, 2016 1:33 pm 
Dies in gote

Posts: 22
Location: NJ
Liked others: 3
Was liked: 8
Rank: DDK
I recently purchased a set of stones and I'm having difficulty identifying the material with which they are made. They are single convex, smooth but not slippery, opaque stones. They were advertised as Melamine, but clearly are not Melamine as I have a double convex set of Melamine stones for travel and I know what they're like. I am doubtful that they are Yunzi, because the black stones have no green glow/luster/aura when put up to bright light, they merely remain opaque. The stones arrived in bags covered in a fine dust, much like Yunzi would. Below is a photo for reference.

https://scontent-sea1-1.xx.fbcdn.net/hphotos-xap1/l/t31.0-8/12829079_10100651255505776_8347478255127567195_o.jpg

Top
 Profile  
 
Offline
 Post subject:
Post #2 Posted: Thu Mar 17, 2016 2:30 pm 
Honinbo
User avatar

Posts: 8859
Location: Santa Barbara, CA
Liked others: 349
Was liked: 2076
GD Posts: 312
Maybe some kind of clay ( or pottery/plaster material ) ?

Are all the stones exactly identical ( i.e. from a mold ),
or, are they slightly irregular, each stone unique ( i.e. made from a drop in heated, liquid form,
then allowed to cool down and naturally flattened by gravity :) ) ?

( Because I have a set like that; Chinese made, quite inexpensive... US$4~5, about a decade ago.
An excellent beginner set -- affordable, and as you place each stone, you make a nice snapping sound. :) )

Hope you enjoy the set.
Quote:
clearly are not Melamine as I have a double convex set of Melamine stones for travel
Close-up photos of both sets for comparison ?

Top
 Profile  
 
Offline
 Post subject: Re: Help Identifying Stones
Post #3 Posted: Thu Mar 17, 2016 2:39 pm 
Dies in gote

Posts: 69
Liked others: 1
Was liked: 14
KGS: FlyingAxe
Tygem: Vincerus
Online playing schedule: ~20:00-24:00 UTC-5
Melamine.

Top
 Profile  
 
Offline
 Post subject:
Post #4 Posted: Thu Mar 17, 2016 2:42 pm 
Honinbo
User avatar

Posts: 8859
Location: Santa Barbara, CA
Liked others: 349
Was liked: 2076
GD Posts: 312
Interesting... melamine

Top
 Profile  
 
Offline
 Post subject: Re:
Post #5 Posted: Thu Mar 17, 2016 2:44 pm 
Dies in gote

Posts: 22
Location: NJ
Liked others: 3
Was liked: 8
Rank: DDK
EdLee wrote:
Are all the stones exactly identical ( i.e. from a mold ),
or, are they slightly irregular, each stone unique ( i.e. made from a drop in heated, liquid form,
then allowed to cool down and naturally flattened by gravity :) ) ?


Thanks for the reply! The stones seem slight irregular. Some of the white stones in particular are slightly flat on one edge. The white stones also seem slightly larger at times than the black stones. Clay is a possibility as would be glass. Regardless of the material, I quite like the set. I would just like to know what they're made out of!

Getting a set of stones (of any kind) for $4-5 is impressive! Granted, it was awhile ago. I originally bought these because they came with Date wood bowls. I wasn't thinking I'd be getting stones worth much with them, I just wanted the bowls, but I actually like the more than the fake-plastic-feeling Melamine stones I purchased before.

Top
 Profile  
 
Offline
 Post subject: Re:
Post #6 Posted: Thu Mar 17, 2016 2:49 pm 
Dies in gote

Posts: 22
Location: NJ
Liked others: 3
Was liked: 8
Rank: DDK
EdLee wrote:
Close-up photos of both sets for comparison ?


The double convex stones are Melamine. The single convex are the ones I'm unsure about. The double convex have a shine to them, they are light and slippery in texture. The single convex stones have a bit of texture/grip, they are not shiny but kind of matte/dull.

http://postimg.org/image/s67jd36c7/

Top
 Profile  
 
Offline
 Post subject: Re: Help Identifying Stones
Post #7 Posted: Sat Mar 19, 2016 6:04 pm 
Dies in gote

Posts: 69
Liked others: 1
Was liked: 14
KGS: FlyingAxe
Tygem: Vincerus
Online playing schedule: ~20:00-24:00 UTC-5
Strangely, I’ve been playing using single-convex melamine stones this weekend, and it left the two fingers on my hand I use to grip the stones itchy. Almost like there is some allergic reaction. (Could also be because the air is dry, and rubbing skin against a dry surface makes it worse. Could also by psychosomatic after realizing that yunzi stones have lead in them — and these look similar.) Never happened with glass or yunzi, in any season. Anyone had the same reaction ever?

Top
 Profile  
 
Offline
 Post subject: Re: Help Identifying Stones
Post #8 Posted: Sat Mar 19, 2016 6:44 pm 
Oza
User avatar

Posts: 2221
Location: Germany
Liked others: 8262
Was liked: 924
Rank: OGS 9k
OGS: trohde
Universal go server handle: trohde
My Jade Yunzi single convex stones do have a green luster, but I thought it were only these, not all Yunzi stones that have them. From the looks I’d say Yunzi, not Melamine. But I’d think it should be possible to distinguish them simply by weight since (IIRC) Melamine is lighter than Yunzi/glas/ceramics.

_________________
“The only difference between me and a madman is that I’m not mad.” — Salvador Dali ★ Play a slooooow correspondence game with me on OGS? :)

Top
 Profile  
 
Offline
 Post subject:
Post #9 Posted: Sat Mar 19, 2016 7:29 pm 
Honinbo
User avatar

Posts: 8859
Location: Santa Barbara, CA
Liked others: 349
Was liked: 2076
GD Posts: 312
Quote:
From the looks I’d say Yunzi, not Melamine. But I’d think it should be possible to distinguish them simply by weight since (IIRC) Melamine is lighter than Yunzi/glas/ceramics.
Hi Tom, I can't tell if it's melamine (before this thread I had never even heard of the term --
I do have a set that greatly resembles the one in the photo. )
But I'm 99.9% sure it's not Yunzi. :)

And I agree with you about the weight/density difference.

Top
 Profile  
 
Offline
 Post subject: Re: Help Identifying Stones
Post #10 Posted: Sat Mar 19, 2016 7:41 pm 
Oza
User avatar

Posts: 2221
Location: Germany
Liked others: 8262
Was liked: 924
Rank: OGS 9k
OGS: trohde
Universal go server handle: trohde
Mh… if we could break one of these stones and see the site of fracture, we could perhaps know—the Yunzi should be glossy/shiny like broken glass (or like obsidian or any volcanite; a few of my Yunzi stones are chipped and shine exactly like that), while the fracture of Melamine would (IIRC) look dull.

(BTW a few decades ago I had a telephone (landline, spiral cable with textile coating, rotary dial “and all”) that was made of Melamine, plus a few small boxes of the same material.)

_________________
“The only difference between me and a madman is that I’m not mad.” — Salvador Dali ★ Play a slooooow correspondence game with me on OGS? :)

Top
 Profile  
 
Offline
 Post subject: Re: Help Identifying Stones
Post #11 Posted: Sun Mar 20, 2016 11:50 pm 
Dies in gote

Posts: 22
Location: NJ
Liked others: 3
Was liked: 8
Rank: DDK
Bonobo wrote:
Yunzi should be glossy/shiny like broken glass... ....Melamine would (IIRC) look dull.


The stones are certainly heavier than the double convex Melamine stones I have. I highly doubt they are Melamine. The lack of "green" was my only indication that they were not Yunzi. I suspect at this point that they are clay. If one breaks I'll let you know, but I don't feel like breaking one just to see ;-)


This post by Ninjaboots was liked by: Bonobo
Top
 Profile  
 
Offline
 Post subject: Re: Help Identifying Stones
Post #12 Posted: Wed Mar 30, 2016 9:29 pm 
Dies in gote

Posts: 69
Liked others: 1
Was liked: 14
KGS: FlyingAxe
Tygem: Vincerus
Online playing schedule: ~20:00-24:00 UTC-5
I purchased two sets of stones from here (one for main play and one as a replacement): http://www.amazon.com/Melamine-Single-C ... sr_ph&sr=1

A couple of stones broke on me, so I took a picture. I imagine that if my countertop broke, it would look sort of like this inside. I agree they feel potentially like clay and not like plastic, but from the inside, I don’t think they look like clay. They look somewhat plasticy and porous, although they feel very similar to yunzi. (The surface is also somewhat porous, which is actually a detriment, as some white stones have lots of dark dots making them look dirty, while some black stones have white and yellow dots. I ended up picking the best stones with the fewest imperfections from both sets that I bought for my main playing set.)

I am fairly convinced these might be the advertised melamine. I would prefer it to be clay though.


Attachments:
melamine_stones.png
melamine_stones.png [ 1.33 MiB | Viewed 6638 times ]

This post by FlyingAxe was liked by: Bonobo
Top
 Profile  
 
Offline
 Post subject: Re: Help Identifying Stones
Post #13 Posted: Thu Mar 31, 2016 12:47 am 
Dies in gote

Posts: 22
Location: NJ
Liked others: 3
Was liked: 8
Rank: DDK
Thanks so much FlyingAxe! I was so doubtful that they were melamine just from the exterior texture, it's great to see the inside of the stones.

I ordered a second set a few days ago as well (but with knit grass bowls instead of wood) and I intended on mixing and matching the two in the same manner, though honestly I do not have many white stones with dark spots etc.

I would prefer clay to melamine as well, however I like how these stones look and feel MUCH more than the other Melamine stones I have. Interestingly enough, the Amazon posting for these stones has the exact same picture as a listing that specifically says YUNZI in the title. It makes me curious if they are being advertised as Yunzi, even though they clearly are not.

Thanks again for taking the time to help me figure it out :bow:

Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 13 posts ] 

All times are UTC - 8 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group