ColoradoProspector   CP Club Membership Info.

Welcome Guest ( Log In | Register )

 
Reply to this topicStart new topic
Mineral learning help
jimmyrig
post Jan 20 2018, 09:00 AM
Post #1


Shovel Buster!
***

Group: Members
Posts: 52
Joined: 28-June 17
From: Ken Caryl
Member No.: 132,619



Was a beautiful day out yesterday so I went out to the hayman burn area to do some poking around and test flight with my drone. I'm still learning my common minerals so thought I'd just take a stab at some. Is this Quartz in Porphyritic Rhyolite?
Attached image(s)
Attached Image
 


--------------------
James
Member Since 06/2017
Referral JB748
Go to the top of the page
 
+Quote Post
jimmyrig
post Jan 21 2018, 09:08 AM
Post #2


Shovel Buster!
***

Group: Members
Posts: 52
Joined: 28-June 17
From: Ken Caryl
Member No.: 132,619



Drone Video https://www.youtube.com/watch?v=w8Xs7ji7Fx0


--------------------
James
Member Since 06/2017
Referral JB748
Go to the top of the page
 
+Quote Post
Woody
post Jan 21 2018, 10:44 PM
Post #3


Rock Bar!
****

Group: Members
Posts: 637
Joined: 5-April 11
From: All of Colorado
Member No.: 15,615



Hi Jimmyrig,

So... Just learning your minerals huh? Well "Porphyritic Rhyolite" is a mouth full for someone just cutting their teeth on common minerals. Rhyolite is very common and can be found all over the high country. "Porphyritic" on the other hand is a term
used to describe the texture of a host of different rocks. The use of the word Porphyritic describing texture is a direct reference to Crystals contained in the material being described. The size of these crystals are most often very small and can't readily be
addressed unless viewed up-close.

From the picture submitted, I can't honestly tell if that material is Rhyolite or Granite, let alone if it is Porphyritic or not. I'd call it an outcropping of Quartz in Granite.

However, I think I know what you are getting at, and I like it! When a dedicated person first takes on a new hobby they read a lot about it. One of the terms used in describing how to find crystals is Porphyritic. If you are seeing this porphyritic texture,
then you are in the right area. If you are not seeing it, then move on to another area or another material. Once you found it, use it to your advantage! Best case scenario.... you come up to a rocky material face and you can see it has a porphyritic texture.
From as far away as possible, "6 inches or 6 feet, whatever the case may be". Observe this texture and try to work-out which direction the crystals are getting bigger. Is it becoming more, or less porphyritic? Follow the direction of the larger crystals and
hopefully it becomes a seem and then a pocket!


If I seen this outcropping of Quartz in anything, Rhyolite or Granite, I'd go poke at it. See what else it had to say?

Hope this was helpful, Woody.



--------------------
Proud CP Lifetime Member
(currently working hard in the procurement department)
Go to the top of the page
 
+Quote Post
GeoMatt
post Jan 22 2018, 12:20 AM
Post #4


Diggin' In!
**

Group: Members
Posts: 43
Joined: 28-July 14
From: Evergreen
Member No.: 117,968



Granite.
Go to the top of the page
 
+Quote Post
jimmyrig
post Jan 22 2018, 04:16 PM
Post #5


Shovel Buster!
***

Group: Members
Posts: 52
Joined: 28-June 17
From: Ken Caryl
Member No.: 132,619



I have found it difficult to tell the difference between granite and rhyolite. Only thing I know is that rhyolite seems to be more porous due to surface cooling and granite is a little more dense?


--------------------
James
Member Since 06/2017
Referral JB748
Go to the top of the page
 
+Quote Post
dbx
post Mar 11 2018, 08:09 PM
Post #6


Diggin' In!
**

Group: Members
Posts: 30
Joined: 8-January 13
From: Denver
Member No.: 51,779



I have been fairly idle in this endeavor, but hoping to find time again to dive in.
I have bought these Geologic Survey Bulletins from a guy in Lakewood, but
found them online as well. I don't realize their full value yet, but they are interesting.
Bulletin


--------------------
-dbx-
Go to the top of the page
 
+Quote Post

Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:

 



Lo-Fi Version Time is now: 28th March 2024 - 04:35 AM