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[Phishisgroovin]

Note, this was taken from http://www.utahrockhounds.com/tooelegem/tips/stonepolish.html a site that is no longer active
For Lapidary Materials
from Benjamin E. Schmidt

Key:   CO – Cerium Oxide, CH – Chrome Oxide, DI – Diamond, LA – Linde A, TO – Tin Oxide
 

Actinolite: TO
Agate:  CO, TO
Alabaster:  TO
Amozonite: TO
Amber: TO
Amblygonite: TO
Andalucite: TO
Apatite: LA, CH
Aventurine: TO
Azurite: TO, CH
Apophyllite: CH
Aragonite: CH
Axinite: CO
Barite: CH
Benitoite: CO
Beryl: CO, TO, DI
Bloodstone: LA
Brazilianite: TO
Calcite: TO, CH
Cassiterite: TO
Celestite: CH
Cerossite: CH
Chrysoberyl: DI
Coral: TO
Corundum: DI
Cubic Zirconia: DI
Danburite: TO
Datolite: TO
Diopside: CH
Dioptase: CO
Diorite: CO, TO, LA, CH
Enstatite: TO
Epidote: TO
Euclase: TO
Feldspar: CO, TO
Fluorite: TO, CH
Garnet: CO, TO, LA, DI, CH
Goldstone: CO, TO
Hematite: CO
Hickoryite: LA
Howlite: CO, TO, LA, CH
Hypersthene: TO
Jadeite: CO, TO, LA, CH
Jasper: CO, TO, LA, CH
Kyanite: TO    Labradorite: TO, CH
Lapis Lazuli: TO, LA, CH
Lepidolite: CH
Limestone: CO, TO, LA, CH
Malachite: TO, LA, CH
Moonstone: TO
Nephrite: TO, LA, CH
Obsidian: TO, CH
Onyx: CO, TO, CH
Opal: CO, TO
Peridot: TO, LA, DI
Petrified Wood: CO, TO, LA, CH
Phenacite: TO
Pollucite: TO
Quartz: CO, TO
Rhodochrosite: TO, LA, CH
Rhodonite: CO, LA, CH
Ruby: DI
Rutile: LA
Sapphire: DI
Scapolite: CO
Scheelite: CH
Serpentine: TO, LA, CH
Smithsonite: TO
Sodalite: CO
Sosolite: CO
Spinel: TO, LA, DI
Spahlerite: CH
Spodumene: TO
Sunstone: TO
Thompsonite: CO
Tiger-eye: CO, TO, LA
Titanite (sphene): TO
Topaz: TO, LA, DI
Tourmaline: TO, LA, DI
Turquoise: CO, TO, LA
Unakite: CO
Varicite: CO, TO, LA
Vesuvianite: CO
Williamsite: LA
Wonderstone: TO, LA,
Wulfenite: CH
Zircon: TO
Zoisite: CO

[Bentiron]

Thanks! That's an extensive list and very helpful. I wish there had been something like this back in 1968 for my neighbor and I when we were trying to make first class cabs. I may  have stuck with it longer then but I don't regret going the metalsmithing route.

[Pebblehopper]

Is there any general guideline to determine what "fabric" to use with each of these compound/stone combinations?


Keep calm and hammer on!

[louisvillelapper]

Great post! David in Indiana

[peruano]

A partial guide to fabric is:
Cerium oxide needs to go on really wet - hence a felt disc that will hold the liquid.
Chromium oxide goes on as a paste on the stone with a spritz once in awhile on a leather backing. 
I have exhausted my expertise on differences in ways to present polishes. 

[Amethyst Rose]

I typically use rough leather pads for all my polishing, be it Cerium, Linde A or Chrome oxide.  I use the Linde on most stones softer than 6 is hardness.  6 and over is Cerium.  Rhodonite or lapis and a few others that won't polish as I want it to, Chrome

Bob Johannes

[finegemdesigns]

Is there any general guideline to determine what "fabric" to use with each of these compound/stone combinations?


Keep calm and hammer on!

I use leather for everything I polish.

[PhilNM]

tin oxide works best  when applied wet to leather. use very sparingly. a little goes a long way.

[bobby1]

I use a carpet covered wheel for most things and a hard wood (black oak) wheel with Rapid Polish for nephrite, lapis and other troublesome materials.
Bob

[RGB776]

I'm using a felt belt on an expandable drum with cerium oxide to polish agate. I first wet the belt with water then apply the cerium as a mud to the stone and start polishing. the belt seems to dry out rather quickly causing the mud to also dry on the belt and the stone. I'm pretty new to this, any pointers on the correct method? Also what is the best way to clean any residual cerium off the nooks and crannies of the stone, it seems to turn to concrete when it dries out!!

[rocks2dust]

Also what is the best way to clean any residual cerium off the nooks and crannies of the stone, it seems to turn to concrete when it dries out!!

Make sure that the felt is damp deep down, and don't apply too much cerium slurry. I think perhaps your cerium is too thick and needs to be thinned. Dampen when the felt itself starts to get dry (some materials polish best when the cerium itself starts to dry, but the felt should still be holding some moisture to avoid getting real hot). For cleaning it off, a soak (give it an hour or so) in dishwashing liquid, followed by a scrub with a brush (a toothbrush does good in small pockets and corners). For jasper, agate and anything but really soft stone (where you usually wouldn't use cerium anyway), you can use ordinary kitchen scouring powder (Ajax, Comet, etc.) with the brush to get the stubborn bits. In druzy vugs, you may need to use a dental pick to loosen it up before scrubbing.

[RGB776]

Thanks for the tips! I bought the cerium from Kingsley and it said to mix it 3 heaping teaspoons to 32 oz of water in a spray bottle. It doesn't seem too thick, it stays puddled on the stone when applied and doesn't run off. I'll try saturating the belt more before polishing and spraying it with water throughout the process. My machine is running about 1750 rpm, I'll try slowing it down. The belt shouldn't slip on the drum at a lower speed as it's a pretty tight fit already.

[gemfeller]

RGB776, I think you're using far too much cerium.  And if there's a way to slow your machine down, do it.  In my opinion oxide polishes should never "cake" on a stone.  If I mix an oxide with water in a spray bottle I usually use another spray bottle with water only to wet the buff first, then spray on a couple of squirts of oxide.  I run my polisher at the slowest speed possible without stalling it (I use an old slant cabber with a rheostat speed control). 

When the stone starts to "grab" it's polishing -- and heating up.  Don't stay at it too long or you'll "cook" the stone or melt the dop wax.  Just spray on a little more water and continue, repeating as often as necessary, adding a few squirts of oxide as needed to get a complete polish.  That method has worked for me for many years.  I cut a lot of opal so I'm extra careful about overheating while polishing.

[RGB776]

Right on, thank you! What ratio do you mix your cerium/water?

[gemfeller]

Right on, thank you! What ratio do you mix your cerium/water?

I don't really measure.  I keep the mixture watery enough so it spritzes easily from a spray bottle without clogging.  The measurements you mentioned seem about right to me.  Polish builds up on the lap and sometimes I don't add any new oxide, just moisten with water before polishing.  If it needs more cerium you'll know pretty fast. 

[MonVictorian]

Hello,

I understand that sugilite is a cyclosilicate mineral.
What category of polish would sugilite fall under?

What category of polish would Labradorite fall under?

thx much in advance....

Regards Monica

[finegemdesigns]

I've used cerium oxide, tin oxide, Poly-Al-F (Polishing Grade Aluminum Oxide) and Linde A.
All work but I think I prefer any of the last 3 over cerium oxide. (For sugilite and labradorite)

[Michael]

These are great reference posts for polishing stones.  At one time I was using a 1725 RPM arbor and various wheels.  Other than diamond, this was way too fast and hot.   The reference to "cooking" the stone, esp with CO is spot on!    Now I have a dedicated arbor that is < than 900 RPM's and I can belt it down for amber and other soft stones up 5 MOHS.  Wish I had this info earlier, and saved a lot of needless work. Thanks to all.