foogy
starting to shine!
Member since October 2012
Posts: 26
|
Post by foogy on Dec 27, 2012 14:23:48 GMT -5
I've had had some Black Agate polishing in Cerium oxide for about 2 weeks and I'm getting mixed results by which I mean some of the stones are looking nice and shiny while the majority of them although lovely and smooth arent showing any signs of a shine, am i doin something wrong or do they just need more time? As always any advice is much appreciated
|
|
herchenx
Cave Dweller
Member since January 2012
Posts: 3,360
|
Post by herchenx on Dec 27, 2012 16:29:50 GMT -5
Hi Foogy,
Do you have any photos? Also, how ready for polish were they when you started them polishing? By that I mean were they all very smooth with no pits or cracks? Were they all evenly hard or was there any matrix on them?
Given that some are all shiny and some are not shiny, I would suspect that maybe you have a mixed batch, meaning some are agates and some are onyx or obsidian.
|
|
foogy
starting to shine!
Member since October 2012
Posts: 26
|
Post by foogy on Dec 27, 2012 17:32:05 GMT -5
I did try to upload a pic but it was about 6mb so wouldnt let me do it. I bought the stones from a company here in the UK and they all looked identical when i first loaded them so would assume they are all the same stuff. They were pretty much smooth as a babys bum when they went into polish so cant figure out why some have polished and others havent
|
|
|
Post by deb193redux on Dec 27, 2012 20:23:14 GMT -5
resize your photo to about 780 x 580, and it will upload, but host it somewhere like photobucket (instructions in members photos section), is better.
|
|
foogy
starting to shine!
Member since October 2012
Posts: 26
|
Post by foogy on Dec 28, 2012 8:44:41 GMT -5
Ive added a pic of the stones to flickr, if anyone wants to see them, my username is Foogy64
|
|
|
Post by deb193redux on Dec 28, 2012 10:40:29 GMT -5
few will do this. take a moment and read up on attaching pics or linking pics. you will have a richer experience here.
|
|
herchenx
Cave Dweller
Member since January 2012
Posts: 3,360
|
Post by herchenx on Dec 28, 2012 12:27:16 GMT -5
Foogy if you enable sharing on your Flickr profile you can use BBCode off your flickr page and easily share photos on here from Flickr. For everyone else, here is the page with the image: www.flickr.com/photos/71590368@N08/8318288228/in/photostreamI think you have mixed hardnesses, meaning that some agate is shiny because it is hardest. The "frosted" stuff is some degree softer. Your rounding generally seems OK but I see some white pitting and cracks that suggest that there may have been some contamination (grit carried forward) Do you have a link to what you ordered?
|
|
foogy
starting to shine!
Member since October 2012
Posts: 26
|
Post by foogy on Dec 28, 2012 17:10:37 GMT -5
I washed the stones in borax for 24hrs before goin into polish for which i have a polish only barrel so not sure about the contamination theory, you can see what I bought by goin to www.ukge.co.uk/UK/rough-rock.asp
|
|
herchenx
Cave Dweller
Member since January 2012
Posts: 3,360
|
Post by herchenx on Dec 29, 2012 13:09:57 GMT -5
hmm, well I'm baffled then. Agates and most jaspers, apart from occasional chipping with certain varieties - never fail to deliver for me. It might be worth hardness testing them to see if they are all the same hardness.
If you do have cracks in the rocks, there is no guarantee that a day in borax would completely remove contamination. I 'pressure wash' some pits if I want to keep them and can get a good deal of contaminant out of cracks and pits, so I can't rule out contamination.
The mixed hardness theory is the most probable based on my experience - if it was just contaminant, all the rocks would be scratched/frosted - the fact that some are shinier than others suggests that some are harder. If you have access to ceramic media you could pull the shiny and cracked rocks out and just do a load of frosted ones with media to fill the barrel, maybe go back to 500 AO for a few days and re-enter polish with just the media and the frosted rocks.
Have you had success with other loads?
|
|
foogy
starting to shine!
Member since October 2012
Posts: 26
|
Post by foogy on Dec 29, 2012 17:55:08 GMT -5
Well just to update you I've taken them out of the cerium oxide today and gave them a good clean and inspected them, there is no pitting or cracks to speak of so just in case the polish was contaminated I've binned it and put them into a fresh batch of cerium oxide to see if that brings them on any. I'm all out of ao at the moment and waiting on some bein delivered so can try that when it arrives if the fresh polish doesnt improve them any. I'm new to this and this is only my 3rd batch of stones but the first 2 batches one of which was just white quartz and the other was a mixed batch of stones i collected from St Martins beach on the Bay of Fundy in Canada while on holiday earlier this year, both these batches turned out really well for my first attempt so was quite encouraged by these results but I'm in no doubt that everyone has ups and downs when starting out so I'll percivere and hopefully get there in the end.
|
|
Deleted
Deleted Member
Member since January 1970
Posts: 0
|
Post by Deleted on Dec 30, 2012 2:01:49 GMT -5
|
|
foogy
starting to shine!
Member since October 2012
Posts: 26
|
Post by foogy on Dec 30, 2012 10:10:27 GMT -5
Ok! this is starting to get complicated! There loads of site selling jewellery and tumbled stones reportedly made of Black agate which look almost identical to the stones I'm trying to polish so are all these sites in the wrong or is Black agate just a commonly used name for this type of Onyx or Chalcedony? I've read a couple of articles online and from what i can gather they are pretty hard to tell apart to an untrained eye ( of which I have two!). So Given that they may be Onyx or Chalcedony should I be treating them any differently in order to get good results?
|
|
quartz
Cave Dweller
breakin' rocks in the hot sun
Member since February 2010
Posts: 3,352
|
Post by quartz on Dec 30, 2012 11:03:25 GMT -5
Unfortunately, your pics. won't come up for me, can't really see what you are dealing with. Agate, onyx, and chalcedony are all the same basic mtl., quartz. Marketing strategy seems to play a big part in what it is called. Based on our tumbling experience, some of it will polish well and some just won't, hardness and microstructure playing a big part in it. On the south coast of Oregon we find pet. wood on the beach, it all looks the same [black and tan] when picked up, some will polish beautifully, and some no better than a brick. We just deal with it, and enjoy the ones that polish well. With the pieces that are sort of "iffy" to polish, we run them very well cushioned with leather scraps, helps the quality. I recently talked with some people who have large rubber bands available for the taking, they said the bands work quite well as a cushioning mtl. Good luck.
|
|
Deleted
Deleted Member
Member since January 1970
Posts: 0
|
Post by Deleted on Dec 30, 2012 13:01:34 GMT -5
Greetings [foogy] Scott in order for a stone to be called an Agate it must be patterned & different colors & is a mineral. Agate, Chalcedony, Onyx, Quartz. If you scroll down to the Varieties section for the minerals above, you will notice that there is no "Black agate" variant, which means "Black agate" does not exist, if it is not in MinDat it is not a mineral! Rhyolite has the colors & fortification banding like an agate, but it is not a mineral, it is an Igneous class rock just like Basalt, Granite & Quartz-Dolerite (Whinstone)! -- I hail from (The Barony of Seabegs) Bonnybridge, Stirlingshire, U.K, where aliens (15mb) sometimes come for a visit & about 4 miles west from this monstrosity! Sticky's: their contents are resource information 1#: Vendors worldwide (2mb), 2#: How to use the forum, 3#: How to identify rocks & minerals, 4#: Save money on expensive grits & polishes!
|
|