Jump to content

Amber? Copal? Any ideas?


Recommended Posts

I inherited a friend's mineral collection. Lot's of interesting specimens of turquoise, petrified wood, crystals, etc. He lived in New Mexico and I know some of the pieces are from U.S. southwest area. That's about all I know. This one's a mystery, and he really didn't have any idea either where it came from. Has a strangely organic look to it though. Any insight or thoughts will be appreciated. Thanks!

IMG_4492.jpg

IMG_4601.jpg

IMG_4602.jpg

IMG_4603.jpg

IMG_4604.jpg

Link to post
Share on other sites
hemipristis

Neither, I'm afraid. It's a gorgeous specimen of agate!  :wub:

 

It resembles Fire Agate, but w/o the fire

  • I found this Informative 4
Link to post
Share on other sites

Thanks! That would make sense. There's some other sliced ones in the collection. Is the weird lumpy shape typical?

Link to post
Share on other sites
hemipristis
7 minutes ago, jhw said:

Thanks! That would make sense. There's some other sliced ones in the collection. Is the weird lumpy shape typical?

The shape is called "botryoidal".  Numerous minerals exhibit this crystal form, and with regards to agate, it is extremely common. 

 

Here are a few examples of other minerals exhibiting this habit, including malachite, calcite, hematite and goethite

US2-cc-300x225.jpg

s-l1600.jpg

be2901078f63a2b6b9f29e579ef7924f.jpg

calm150-calcite-speleothem-decorator-specimen.jpg

  • I found this Informative 3
Link to post
Share on other sites
Mark Kmiecik

Copal is flammable, and should melt before it ignites. This does look more geological. Carnelian?

Link to post
Share on other sites
abyssunder

I have never seen amber with botryoidal crescents, so I'm leaning toward a harder material which may have that pattern. It may have a silica-rich material, in my thinking.

  • I found this Informative 1
Link to post
Share on other sites
1 hour ago, hemipristis said:

Neither, I'm afraid. It's a gorgeous specimen of agate!  :wub:

 

It resembles Fire Agate, but w/o the fire

+1 I’m with hemipristis it’s geologic in origin likely an agate. Really beautiful specimen too

  • I found this Informative 1
Link to post
Share on other sites
Sagebrush Steve
1 hour ago, hemipristis said:

Neither, I'm afraid. It's a gorgeous specimen of agate!  :wub:

 

It resembles Fire Agate, but w/o the fire

Yes, it’s fire agate, possibly from Arizona.  We used to collect it in a place called Saddle Mountain many, many, many years ago.

  • I found this Informative 2
Link to post
Share on other sites
hemipristis
9 hours ago, jhw said:

Thank you sir!

For educational purposes, a few more 'tests'/observations that will help distinguish:

 

Amber/copal are chemically almost natural styrene plastic. As such, they will be very lightweight and soft. A pin or nail will scratch them. One can polish them with toothpaste. Agate/chalcedony in contrast represent varieties of microcrystalline quartz, and will feel, well, as heavy a as a rock, LOL.  They will also be sufficiently hard that a pin or nail will not scratch it, and will scratch glass.

  • I found this Informative 1
Link to post
Share on other sites

A quick easy test for amber is to mix 2 cup warm water with 1/4 cup salt. Real amber will float. Copal and most other objects will sink.

  • I found this Informative 2
Link to post
Share on other sites
hemipristis
1 hour ago, Randyw said:

A quick easy test for amber is to mix 2 cup warm water with 1/4 cup salt. Real amber will float. Copal and most other objects will sink.

Didn't know that trick.  Thanks

Link to post
Share on other sites
3 hours ago, JohnBrewer said:

@ynot May be able to shed some geological light. 

Don't know what I could say that has not already been said.

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...