collapse

Author Topic: Topaz?  (Read 4024 times)

cohen95

  • ALF'er Bronze Member
  • *
  • Posts: 9
Topaz?
« on: November 22, 2017, 03:05:15 PM »
Here’s a stone I found in the bunyip river district
It has some nice square faces on it and a termination.
I have done a hardness test against known topaz pieces
And they appear to leave no marking,
The dark colour has thrown me off
It may just be because it’s covered in other material that it appears so dark

What do you think topaz or just quartz?

20 cent coin for size reference








Jimnyjerry

  • Global Moderator
  • ALF'er VIP
  • *****
  • Posts: 2673
  • balts pingvins
Re: Topaz?
« Reply #1 on: November 22, 2017, 04:49:45 PM »
Hi Cohen95  :)

Check this link out for topaz  http://aussielapidaryforum.com/forum/index.php?topic=1974.0

Hard to tell what your stone is.  Cannot see any striations parallel to the crystal growth.

I try to take one day at a time, but sometimes several days attack me at once.

Gem Ranger

  • ALF'er Platinum
  • *
  • Posts: 268
Re: Topaz?
« Reply #2 on: November 22, 2017, 07:15:55 PM »
Its definitely quartz Cohen, sorry. I've fossicked a lot of it over the years.

GR

cohen95

  • ALF'er Bronze Member
  • *
  • Posts: 9
Re: Topaz?
« Reply #3 on: November 22, 2017, 07:36:51 PM »
Quartz was definitely my first pick just the hardness and shape had me questioning myself :)

Mouse

  • ALF'er Silver Member
  • *
  • Posts: 94
  • Here for a good time, not a long time!
Re: Topaz?
« Reply #4 on: November 30, 2017, 11:01:27 PM »
Hi Cohen, I recall reading something in my distant past that if the crystal shape was pretty obvious and it was 4 sided (squarish), it was topaz, if it was 6 sided (hexagonal) it was quartz. That's what I use as a quick guide when fossicking, however I don't throw anything away until I have done a specific gravity (SG) test http://aussielapidaryforum.com/forum/Smileys/classic/undecided.gif.
Looking at your middle 2 photos I would have said Topaz but the last photo put some doubt in my mind.
To do an SG test
1. Weigh the dry stone (write the weight down)
2. Fill a container with water on the scales and set them to zero.
3. Suspend the stone in the water (don't touch the sides or bottom) and write down the weight.
4. Divide the first figure by the second figure.
If you get an answer around 2.65-2.72 it's Qz. If you get an answer around 3.5 it's Topaz. The results are not always exact but near enough to make a decision.
I've found the hardness test is often difficult to do and see a result.
I have a simple SG test kit that we take with us and check everything before we make a decision. It consists of a sealable container, magnifying eyepiece and a piece of solder to flatten or shape to suspend the stone.
My scales also have a quick reference sheet of the more common SG's and hardness'.
Hope this helps.
Regards
Mouse
Life is not all about the final destination, but the journey taken.

scratchie

  • ALF'er Gold Member
  • *
  • Posts: 173
Re: Topaz?
« Reply #5 on: December 01, 2017, 03:41:23 PM »
re SG test ,
I think you've missed a step - you have to find the difference in the weight in air and the weight in water and then do your division
Jon

Aussie Sapphire

  • Global Moderator
  • ALF'er VIP
  • *****
  • Posts: 3354
    • Aussie Sapphire
Re: Topaz?
« Reply #6 on: December 01, 2017, 03:46:35 PM »
This thread contains a link to a document with detailed instructions on measuring SG.


http://aussielapidaryforum.com/forum/index.php?topic=1137.15


There are also useful Youtube videos.


cheers
Leah

Aussie Sapphire - The Lapidary Warehouse

Jamo

  • ALF'er VIP
  • *
  • Posts: 1706
  • Gippsland Rocks!
Re: Topaz?
« Reply #7 on: December 03, 2017, 09:17:38 PM »
Cohen if you are in the area of Warragul Lapidary Club please drop in and we could identify it for you.
Baaa humbug, not enough fossicking time!

 

Recent Activities

Nundle - Fossicking Access to the Peel River by opal light
[Today at 10:07:16 AM]


Blue Hills quarry and Sapphire bend access at Oberon by opal light
[Today at 09:46:26 AM]


Armidale to Tenterfield by Bucket
[March 28, 2024, 02:40:56 PM]


Recently cut gems (AB Facet Designs) by mehoose
[March 28, 2024, 01:41:37 AM]


New mast and quill assembly by RoughCreations
[March 27, 2024, 08:46:05 AM]


Lapidary Industry Turmoil in the USA by tinker
[March 26, 2024, 02:48:04 PM]


Garnet by RoughCreations
[March 26, 2024, 11:13:38 AM]


Faceting machine head assembly. by Faceting Frank
[March 21, 2024, 09:56:28 AM]


Apex Indexer by RoughCreations
[March 20, 2024, 11:53:34 AM]


Club Badges or Pins by Suparoo
[March 16, 2024, 07:39:39 AM]


vib flat lap restoration by lewy
[March 10, 2024, 09:35:09 PM]


Save the Gemfields. by pc bowe
[March 09, 2024, 05:34:58 PM]


Novice in need of advice on Opal by Bucket
[March 09, 2024, 03:28:07 PM]


Glen Innes, Mud maps and private property by MrSydney
[March 08, 2024, 02:38:53 PM]


18ct Wedding Ring by Rusted
[March 08, 2024, 10:22:07 AM]

SimplePortal 2.3.7 © 2008-2024, SimplePortal