Lapidaryforum.net

Please login or register.

Login with username, password and session length
Advanced search  

News:

Welcome new members & old from the Lapidary/Gemstone Community Forum. Please join up. You will be approved after spam check & you must manually activate your acct with the link in your email

Congratulations to gemfeller and his Willow Creek Jasper Cab!

 www.lapidaryforum.net

Another cabochon contest coming soon!

Poll

Which is better or are they the same?

Left Tear Drop has better polish
- 3 (27.3%)
Right Kite has better polish
- 5 (45.5%)
Same - Polish is equal on both gems
- 3 (27.3%)

Total Members Voted: 11

Voting closed: January 09, 2018, 11:57:34 AM


Pages: 1 [2]   Go Down

Author Topic: 2 Polishing techniques - Which is better or are they the same?  (Read 332 times)

0 Members and 1 Guest are viewing this topic.

finegemdesigns

  • Full Member
  • ***
  • Offline Offline
  • Posts: 138
    • finegemdesigns
Re: 2 Polishing techniques - Which is better or are they the same?
« Reply #15 on: January 08, 2018, 09:16:49 PM »

Left Tear Drop was polished with 14,000-50,000-100,000 diamond.

Right Kite was polished with Linde A sapphire powder.

Thanks to everyone who participated.

Which has better polish?

Voting here:
Left Tear Drop = 3
Right Kite = 5
Same = 3

youtube votes - Right Kite is better = 1

Totals:

Left Tear Drop = 3
Right Kite = 6
Same = 3
Logged

vitzitziltecpatl

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 448
Re: 2 Polishing techniques - Which is better or are they the same?
« Reply #16 on: January 09, 2018, 06:06:03 AM »

One more question about the polishing methods.

What type of lap (or wheel) was used for the diamond on the teardrop?

finegemdesigns

  • Full Member
  • ***
  • Offline Offline
  • Posts: 138
    • finegemdesigns
Re: 2 Polishing techniques - Which is better or are they the same?
« Reply #17 on: January 09, 2018, 11:18:54 AM »

One more question about the polishing methods.

What type of lap (or wheel) was used for the diamond on the teardrop?

It's a canvas pad like the one shown here:

https://www.kingsleynorth.com/skshop/product.php?id=96664&catID=1055

Logged

lapidaryrough

  • Full Member
  • ***
  • Offline Offline
  • Posts: 141
    • www.lapidaryrough.com
Re: 2 Polishing techniques - Which is better or are they the same?
« Reply #18 on: January 09, 2018, 02:22:45 PM »

Material used looks to have a un-stabilized  surface, meaning hard an soft formation zones in material causing a under cutting of material during cabbing.
soft backing on pad well cause polish to carve deep concave dishing on the surface.

   Wood polish wheels ( Maple clear grain ) are best for leveling the dome, Then the felt or wool pad - with your call of polish.

    Jack 
Logged
Silicate life form

gemfeller

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 351
    • Art Cut Gems
Re: 2 Polishing techniques - Which is better or are they the same?
« Reply #19 on: January 09, 2018, 03:35:07 PM »

Jack, do you know of anyone who sells maple wheels?  I used to have a couple but they were taken in a burglary.  I'd have some made but don't know anyone who does that kind of woodwork locally.
TIA, Rick
Logged

finegemdesigns

  • Full Member
  • ***
  • Offline Offline
  • Posts: 138
    • finegemdesigns
Re: 2 Polishing techniques - Which is better or are they the same?
« Reply #20 on: January 09, 2018, 04:09:30 PM »

Material used looks to have a un-stabilized  surface, meaning hard an soft formation zones in material causing a under cutting of material during cabbing.
soft backing on pad well cause polish to carve deep concave dishing on the surface.

   Wood polish wheels ( Maple clear grain ) are best for leveling the dome, Then the felt or wool pad - with your call of polish.

    Jack

I appreciate your input but I'm not convinced that the theories involving undercutting and orange-peel are accurate. For example I have read pages where people believe that you can stop undercutting by use of different techniques and polishing. IMO there are physical characteristics that make this virtually impossible in some rocks like chrysocolla in quartz. You have softer 4-5 MOHs particles of chrysocolla floating in hard 7 MOHs gate. By definition a surface imbedded with abrasives will cut the agate slower than the chrysocolla thus creating lower surface areas on a polished surface. But is this really a problem? Really? I can cut and polish chrysocolla in quartz easily and it looks fine top down when viewed.



Also nobody seems to have a problem with other gems like jaspers and turquoise that contain minerals of different MOHs that have minor surface undercutting. The only argument I can see is if you are cutting with a super hard polishing surface like phenolic and you are employing some kind of stop like in faceting. In this case it might be possible to keep undercutting to an absolute minimum. Again we are talking cabochons here not faceted diamonds or rubies.

As far as this experiment it is apparent that the lavender jadeite does have some slight inconsistency in MOHs and also some chatoyancy that makes it difficult to get a perfect mirrored polished surface reflection. Remember though that these are FLATS not curved surfaces. I have a handpiece of the same rough with curved surfaces that are more glassy which is expected. I can probably make a video of this later so people can compare.
Logged

jerrysg

  • Full Member
  • ***
  • Offline Offline
  • Posts: 154
Re: 2 Polishing techniques - Which is better or are they the same?
« Reply #21 on: January 09, 2018, 08:25:34 PM »

Jack, do you know of anyone who sells maple wheels?  I used to have a couple but they were taken in a burglary.  I'd have some made but don't know anyone who does that kind of woodwork locally.
TIA, Rick

Don't know where you are located but if it's anywhere near a large city, my suggestion would be to find either a wood workers supply or a lumber yard that sells a variety of hard woods. Ask them to direct you to the local wood turners club and then ask them who could make what you want. Here in the Tucson area the local wood turners society meets at Woodworkers Source every month so the contact would be easy.

Jerry
Logged

southerly

  • Full Member
  • ***
  • Offline Offline
  • Posts: 145
Re: 2 Polishing techniques - Which is better or are they the same?
« Reply #22 on: January 10, 2018, 09:11:18 AM »

Re under cutting, the sphere making process often seems to produce the best results on material prone to undercutting, presumably because the sphere cutting equipment produces a very even pressure across the whole stone, where as manually cut stones have uneven pressure applied to them allowing fibres, soft spots etc to under cut. CNC carved jade also seems to avoid undercutting, probably for the same reason.

David
Logged

gemfeller

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 351
    • Art Cut Gems
Re: 2 Polishing techniques - Which is better or are they the same?
« Reply #23 on: January 10, 2018, 12:09:05 PM »

Jack, do you know of anyone who sells maple wheels?  I used to have a couple but they were taken in a burglary.  I'd have some made but don't know anyone who does that kind of woodwork locally.
TIA, Rick

Don't know where you are located but if it's anywhere near a large city, my suggestion would be to find either a wood workers supply or a lumber yard that sells a variety of hard woods. Ask them to direct you to the local wood turners club and then ask them who could make what you want. Here in the Tucson area the local wood turners society meets at Woodworkers Source every month so the contact would be easy.

Jerry

Thanks Jerry.  I'll follow through on that.  Hadn't thought of it.
Logged

finegemdesigns

  • Full Member
  • ***
  • Offline Offline
  • Posts: 138
    • finegemdesigns
Re: 2 Polishing techniques - Which is better or are they the same?
« Reply #24 on: January 13, 2018, 12:22:25 PM »

Here is a video showing more reflective surfaces of polished lavender jadeite.

https://www.youtube.com/watch?v=Tpx154Sa_Ps

 :idea1:
Logged
Pages: 1 [2]   Go Up
 

Page created in 0.417 seconds with 43 queries.