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Author Topic: Coffee Mug?  (Read 3409 times)

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cobbledstones

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Coffee Mug?
« on: July 07, 2016, 10:49:27 AM »

Ok, so this summer I want to challenge myself.  My personal challenge: carve a coffee mug with handle.  I have a plan of attack sketched out, and I have 'started', meaning that I am actively looking for fracture free material that is of appropriate size.  This has proved troublesome.  So far, all of the large enough agate chunks I have in stock have been cracked to some degree at critical points.  So I am looking for advice. 

What material do you think would make a good mug?  No strange heavy metals, typically found with fewer fractures in sufficient size.  Of course I would like something nice looking as well. 

My initial thoughts were: big Brazilian nodule, Obsidian, or maybe jade. I have also seen some picture jaspers that could foot the bill. I am willing to invest in a higher quality material to get a nicer final result.  Would love to hear your opinions, and I will document the whole process here.
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rocks2dust

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Re: Coffee Mug?
« Reply #1 on: July 07, 2016, 11:57:09 AM »

If this mug will actually be used, you have to consider the acid and stain resistance of the material. If it can be dyed, then staining may also occur over time (that would rule out agate, quartz, travertine, alabaster, "onyx" and others, IMO). Some like soapstone can be sealed using a food-grade oil, but this has to be repeated frequently. Others like jade are tough, but oils in things like skin or coffee tend to discolor over time. As an amorphous material, obsidian might prove best but even with obsidian, some pieces are going to be more resistant to staining than others (some of the nicely patterned pieces have mineral layers and/or micro-bubble layers that stuff might be able to get into). You might want to do a test on a scrap piece with acidic juice, coffee and tea before actually committing to using the mug.
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Jhon P

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Re: Coffee Mug?
« Reply #2 on: July 07, 2016, 01:04:47 PM »

Take a some of what you want to use and soak it in strong coffee for a week and see want happens. I would not do obsidian, it has a tendency to scratch. May be there is a way to seal the inside with a food grade enamel? Or something
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rocks2dust

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Re: Coffee Mug?
« Reply #3 on: July 07, 2016, 02:36:17 PM »

Most obsidian is going to be harder than the lead glass crystal or ceramic glaze on other dining ware, though. It (and many other gemstone materials) does tend to scratch when thrown into a jewelry box with mixed hardness gemstones, knocked around a lot or polished with pads contaminated with tiny bits of harder stuff. Soaking in strong coffee would be a good idea. Things like copper sulfate or cupric chloride (you can find in concrete stains at your masonry center) act faster to show how a material will uptake staining agents - amazing how fast some stuff you'd think was impermeable will soak up color.

If the cup is not going to be used for drinking or holding liquids, alabaster and soapstone are easy to carve. Alabaster has a nice semi-translucent glow, comes in affordable blocks in varied patterns/colors and takes a nice polish. Both get made into cups, bowls and dishes - but do have to be sealed and even then don't do well with staining, which is why I brought up that concern. Marbles are similar, but a bit harder. Rhodonite, labradorite, sodalite, tigereye, fluorite, milky & rose quartz and petrified wood can be found in block form. For something tougher to carve, but tougher to break, quartzite and nephrite also come in block form. Did you get any Polka Dot in a chunk large enough for a mug? The folks at Richardson's do cores of various materials for spheres, and the smaller cores would work for a mug. Might be worth a trip back there if you can recall something they had on-hand that would work. Healed formation fractures and veils in quartz, agate and similar material are pattern, and shouldn't affect the stability of your piece.
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cobbledstones

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Re: Coffee Mug?
« Reply #4 on: July 07, 2016, 03:15:26 PM »

I hadn't thought about staining, so thank you!  My plan for the mug is light duty use.  I only drink herbal teas, no coffee.  I agree that scratching is less of a concern for a mug as opposed to a ring or other jewelry application that would see constant impact.  I am also looking for a challenge, so alabaster is out on principle.

I did get some nice blocky chunks of polka dot right from the mine.  They break it up with a jackhammer, so the pieces I have cut do have non-healed fractures.  I had one piece that I thought was perfect, but it had 1 and only 1 fracture right through the middle.  Beautiful stuff, and I do have some more blocks to check.  I have one piece of mahogony obsidian with nice pattern that appears crack free, I am currently performing some test cuts to be sure.  I also have some pieces from Richardson's ranch, and can go back if I need to.  It is only a 3.5 hour drive from me.  I had not considered quartzite, nice idea.

my thought process
obsidian: easier to carve than agate, may be less prone to staining, can be found in neat patterns
agate: may be coolest aesthetically, harder to find without fracture, prone to staining
Jade: less likely to break if I drop the mug, expensive and prone to staining
onyx: would rather use agate
Alabaster: not enough challenge
Labrodite: now that is an interesting idea, would be easier to carve, and would flash if cut correctly.
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rocks2dust

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Re: Coffee Mug?
« Reply #5 on: July 07, 2016, 03:56:07 PM »

For herb tea, perhaps something like carnelian agate from around Sweet Home and Lebanon wouldn't show much staining if you could hound a dark-red piece. But since it's YOU who will be drinking from it, I'd go with a bezoar cup - you don't want anyone poisoning you, and they are so ugly, who cares if they stain :shocked:
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Slabbercabber

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Re: Coffee Mug?
« Reply #6 on: July 07, 2016, 04:37:11 PM »

I've thought about it myself and even have a perfect boulder of polka dot for the purpose.  I haven't done it because I can't imagine the amount of grinding that would need to be done to hollow out the cup.  I believe obsidian would be a far better choice both for stains and for carving.
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irockhound

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Re: Coffee Mug?
« Reply #7 on: July 07, 2016, 04:45:07 PM »

If you used Smoky Quartz you might get a double win.  With the smoky it would be hard to tell any stains from the color of the Quartz and second from the side you could see if you need a refill!
I would not recommend soapstone one because of it's softness and watch for asbestos although it may be a small chance in good solid soapstone.

As I have been sitting here thinking I believe if I were to make such a project I would choose petrified wood.  It would have great grain and pattern and Pet. wood is easy to come by in large pieces.  Can you imagine a Petrified Palm fiber or Palm Root mug or some colorful Hubbard Basin material. 
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GoodEarth

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Re: Coffee Mug?
« Reply #8 on: July 18, 2016, 04:14:10 PM »

One of Franks giant Variolites would fit the bill. I know he was planning a series of bowls from the big blue-green one, but the black-grey ones are very nice too. Search here for variolite, and I'm sure some pics will come up.

Sent from my SM-G900V using Tapatalk

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Redrummd

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Re: Coffee Mug?
« Reply #9 on: July 19, 2016, 08:18:11 AM »

A lower cost dark Jade: 1) would not stain 2) will survive a drop 3) easy to do a hand "suede" polish for the inside and handle with automotive wettable sandpaper which comes as fine a 2000 grit.

Fairly easy to find dark Jade too.

Rockoteer

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Re: Coffee Mug?
« Reply #10 on: July 19, 2016, 08:20:06 AM »

A lower cost dark Jade: 1) would not stain 2) will survive a drop 3) easy to do a hand "suede" polish for the inside and handle with automotive wettable sandpaper which comes as fine a 2000 grit.

Fairly easy to find dark Jade too.

There you go .....
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cobbledstones

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Re: Coffee Mug?
« Reply #11 on: July 19, 2016, 06:35:02 PM »

excellent idea, i will start looking for some dark jade
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