Causes of Iridescence in Natural Quartz

vegasjames no longer being taken for granite Member since June 2013 Posts: 9,567	Causes of Iridescence in Natural Quartz Jan 31, 2022 5:10:23 GMT -5 Quote Select Post Deselect Post Link to Post Member Give Gift Back to Top Post by vegasjames on Jan 31, 2022 5:10:23 GMT -5 www.gia.edu/gems-gemology/spring-2017-iridescence-natural-quartz

jamesp
Cave Dweller

Member since October 2012
Posts: 36,607

Causes of Iridescence in Natural Quartz Jan 31, 2022 15:20:07 GMT -5 vegasjames likes this

Quote

Ever notice clear slabs of botryoidal agates have a sort of iridescence ? Often in slabs of transparent Brazilian agate...

Diffraction grating James. 25,400 lines per inch etched in a saw tooth fashion into mylar.

www.edmundoptics.com/p/25400-linesinch-6quot-x-12quot-sheets-2pack/4621?gclid=Cj0KCQiArt6PBhCoARIsAMF5wagqMeQJUuhjaqgpMZmCoxtNc_E3zDiwBej8E9es9BuKgcD79YFN_4EaAtGREALw_wcB

quickie spectroscope using diffraction grating and cell phone

Last Edit: Jan 31, 2022 15:38:50 GMT -5 by jamesp

vegasjames
no longer being taken for granite

Member since June 2013
Posts: 9,567

Causes of Iridescence in Natural Quartz Jan 31, 2022 17:02:50 GMT -5

Quote

Ever notice clear slabs of botryoidal agates have a sort of iridescence ? Often in slabs of transparent Brazilian agate...

Diffraction grating James. 25,400 lines per inch etched in a saw tooth fashion into mylar.

www.edmundoptics.com/p/25400-linesinch-6quot-x-12quot-sheets-2pack/4621?gclid=Cj0KCQiArt6PBhCoARIsAMF5wagqMeQJUuhjaqgpMZmCoxtNc_E3zDiwBej8E9es9BuKgcD79YFN_4EaAtGREALw_wcB

quickie spectroscope using diffraction grating and cell phone

Have not slabbed any so never noticed that.

jamesp
Cave Dweller

Member since October 2012
Posts: 36,607

Causes of Iridescence in Natural Quartz Jan 31, 2022 20:43:36 GMT -5 catskillrocks, vegasjames, and 1 more like this

Quote

Ever notice clear slabs of botryoidal agates have a sort of iridescence ? Often in slabs of transparent Brazilian agate...

Diffraction grating James. 25,400 lines per inch etched in a saw tooth fashion into mylar.

www.edmundoptics.com/p/25400-linesinch-6quot-x-12quot-sheets-2pack/4621?gclid=Cj0KCQiArt6PBhCoARIsAMF5wagqMeQJUuhjaqgpMZmCoxtNc_E3zDiwBej8E9es9BuKgcD79YFN_4EaAtGREALw_wcB

quickie spectroscope using diffraction grating and cell phone

Have not slabbed any so never noticed that.

This effect. Brazil

Condor

This might be iris effect. Not sure if it is the same effect.

Last Edit: Jan 31, 2022 20:47:57 GMT -5 by jamesp

jamesp Cave Dweller Member since October 2012 Posts: 36,607	Causes of Iridescence in Natural Quartz Feb 1, 2022 2:29:58 GMT -5 Quote Select Post Deselect Post Link to Post Member Give Gift Back to Top Post by jamesp on Feb 1, 2022 2:29:58 GMT -5 Perhaps the iris effect is due to transmission and iridescence is a reflected effect vegasjames. Did not mean to sidetrack. Either way they are both spectral phenomena...
	Last Edit: Feb 1, 2022 2:30:27 GMT -5 by jamesp

vegasjames no longer being taken for granite Member since June 2013 Posts: 9,567	Causes of Iridescence in Natural Quartz Feb 1, 2022 3:15:01 GMT -5 Quote Select Post Deselect Post Link to Post Member Give Gift Back to Top Post by vegasjames on Feb 1, 2022 3:15:01 GMT -5 There is an explanation in this link geology.com/stories/13/iris-agate/