Empathy List Archives

MK

Matt Kohn

Tue, Oct 7, 2025 9:10 PM

Hi,

I’m fact-checking some text for an Idaho Public Television science program (for kids), and the question has come up: where do star garnets come from? Obviously Idaho (it’s our state gem), but otherwise…?

If you scan the internet, it says there are only 2 places worldwide: Idaho and northern India.

But, when I search on Google Scholar, all I turn up, in addition to Idaho, is Madagascar and Tanzania. No obvious sites in India.

I don’t need an exhaustive list of star garnet localities worldwide, but:

Is there actually a locality in northern India? Where is that?
Is there any place worldwide, other than Idaho, where star garnets are fairly common?

Thanks for any info,

Matt

Note: While I may send email outside of regular business hours, I do not expect the same from others.

Dr. Matthew J. Kohn, University Distinguished Professor
Department of Geosciences, Boise State University
1910 University Dr.; MS1535
Boise, ID 83725-1535
mattkohn@boisestate.edu
https://www.boisestate.edu/earth/people/matthew-j-kohn/
fax: (208)-426-4061
Pronouns: He/him/his
China book:
https://www.amazon.com/dp/B0BRXWNTS6,
https://www.amazon.com/dp/B0BRZ2XRV9
Optical Mineralogy Book:
https://optical.minpet.org/
Petrology and Plate Tectonics Book:
https://global.oup.com/academic/product/petrology-and-plate-tectonics-9780190490645

Hi, I’m fact-checking some text for an Idaho Public Television science program (for kids), and the question has come up: where do star garnets come from? Obviously Idaho (it’s our state gem), but otherwise…? If you scan the internet, it says there are only 2 places worldwide: Idaho and northern India. But, when I search on Google Scholar, all I turn up, in addition to Idaho, is Madagascar and Tanzania. No obvious sites in India. I don’t need an exhaustive list of star garnet localities worldwide, but: 1. Is there actually a locality in northern India? Where is that? 2. Is there any place worldwide, other than Idaho, where star garnets are fairly common? Thanks for any info, Matt Note: While I may send email outside of regular business hours, I do not expect the same from others. ******************************************************************************************************************************* Dr. Matthew J. Kohn, University Distinguished Professor Department of Geosciences, Boise State University 1910 University Dr.; MS1535 Boise, ID 83725-1535 mattkohn@boisestate.edu https://www.boisestate.edu/earth/people/matthew-j-kohn/ fax: (208)-426-4061 Pronouns: He/him/his China book: https://www.amazon.com/dp/B0BRXWNTS6, https://www.amazon.com/dp/B0BRZ2XRV9 Optical Mineralogy Book: https://optical.minpet.org/ Petrology and Plate Tectonics Book: https://global.oup.com/academic/product/petrology-and-plate-tectonics-9780190490645 *******************************************************************************************************************************

DW

Donna Whitney

Wed, Oct 8, 2025 1:11 PM

Matt,

There are star garnets in the South Mountains of North Carolina. There
doesn't seem to be a lot known about that locality, but some polished
garnets that I saw from there exhibited asterism.

If anyone has information about the metamorphic history of that locality, I
would be very interested to know more. The rock is a garnet-sillimanite
schist.

Donna

On Wed, Oct 8, 2025 at 5:39 AM Matt Kohn via MSA-talk msa-talk@minlists.org
wrote:

Hi,

I’m fact-checking some text for an Idaho Public Television science program
(for kids), and the question has come up: where do star garnets come from?
Obviously Idaho (it’s our state gem), but otherwise…?

If you scan the internet, it says there are only 2 places worldwide: Idaho
and northern India.

But, when I search on Google Scholar, all I turn up, in addition to Idaho,
is Madagascar and Tanzania. No obvious sites in India.

I don’t need an exhaustive list of star garnet localities worldwide, but:

Is there actually a locality in northern India? Where is that?
Is there any place worldwide, other than Idaho, where star garnets are
fairly common?

Thanks for any info,

Matt

Note: While I may send email outside of regular business hours, I do not
expect the same from others.

Dr. Matthew J. Kohn, University Distinguished Professor
Department of Geosciences, Boise State University
1910 University Dr.; MS1535
Boise, ID 83725-1535
mattkohn@boisestate.edu
https://www.boisestate.edu/earth/people/matthew-j-kohn/
fax: (208)-426-4061
Pronouns: He/him/his
China book:
https://www.amazon.com/dp/B0BRXWNTS6,
https://www.amazon.com/dp/B0BRZ2XRV9
Optical Mineralogy Book:
https://optical.minpet.org/
Petrology and Plate Tectonics Book:

https://global.oup.com/academic/product/petrology-and-plate-tectonics-9780190490645

MSA-talk mailing list -- msa-talk@minlists.org
To unsubscribe send an email to msa-talk-leave@minlists.org

Matt, There are star garnets in the South Mountains of North Carolina. There doesn't seem to be a lot known about that locality, but some polished garnets that I saw from there exhibited asterism. If anyone has information about the metamorphic history of that locality, I would be very interested to know more. The rock is a garnet-sillimanite schist. Donna On Wed, Oct 8, 2025 at 5:39 AM Matt Kohn via MSA-talk <msa-talk@minlists.org> wrote: > Hi, > > I’m fact-checking some text for an Idaho Public Television science program > (for kids), and the question has come up: where do star garnets come from? > Obviously Idaho (it’s our state gem), but otherwise…? > > If you scan the internet, it says there are only 2 places worldwide: Idaho > and northern India. > > But, when I search on Google Scholar, all I turn up, in addition to Idaho, > is Madagascar and Tanzania. No obvious sites in India. > > I don’t need an exhaustive list of star garnet localities worldwide, but: > 1. Is there actually a locality in northern India? Where is that? > 2. Is there any place worldwide, other than Idaho, where star garnets are > fairly common? > > Thanks for any info, > > Matt > > Note: While I may send email outside of regular business hours, I do not > expect the same from others. > > ******************************************************************************************************************************* > Dr. Matthew J. Kohn, University Distinguished Professor > Department of Geosciences, Boise State University > 1910 University Dr.; MS1535 > Boise, ID 83725-1535 > mattkohn@boisestate.edu > https://www.boisestate.edu/earth/people/matthew-j-kohn/ > fax: (208)-426-4061 > Pronouns: He/him/his > China book: > https://www.amazon.com/dp/B0BRXWNTS6, > https://www.amazon.com/dp/B0BRZ2XRV9 > Optical Mineralogy Book: > https://optical.minpet.org/ > Petrology and Plate Tectonics Book: > > https://global.oup.com/academic/product/petrology-and-plate-tectonics-9780190490645 > > ******************************************************************************************************************************* > > _______________________________________________ > MSA-talk mailing list -- msa-talk@minlists.org > To unsubscribe send an email to msa-talk-leave@minlists.org >

DK

Duncan Keller

Wed, Oct 8, 2025 3:14 PM

Hi Matt et al.,

There are star garnets reported from quite a few localities worldwide. Most
information is in the gemological literature. Other than Idaho, Madagascar
is the place where star garnets seem to be the most widespread. The
references below have photos of specimens and localities:

northern Idaho, USA (Guinel and Norton 2006 Journal of Materials
Science)
the Phu Tho province of Vietnam (Tien and Nhan 2024 Gem News
International)
the Singida region of Tanzania (Kammerling and Koivula 1990 Journal
of Gemmology)
the Ambatondrazaka and Ihosy districts of Madagascar (Schmetzer et al.
2002 Journal of Gemmology)
and several unspecified localities in India (Schmetzer et al.
2002 Journal
of Gemmology)

The Indian localities seem to be poorly documented compared to the rest. I
haven't seen the North Carolina locality Donna mentioned, but I'm also
interested to hear if folks have information on it. Very cool.

If you're interested in the other examples of oriented rutile needles in
garnet, Keller and Ague (2020) has a compilation of the documented
localities as of the time of publication. There have been several others
documented since, and I know from personal communications that more are
known but not published. (Ultra)high-pressure and (ultra)high-temperature
groups both exist.

Best,
Duncan

On Wed, Oct 8, 2025 at 6:42 AM Matt Kohn via MSA-talk msa-talk@minlists.org
wrote:

Hi,

I’m fact-checking some text for an Idaho Public Television science program
(for kids), and the question has come up: where do star garnets come from?
Obviously Idaho (it’s our state gem), but otherwise…?

If you scan the internet, it says there are only 2 places worldwide: Idaho
and northern India.

But, when I search on Google Scholar, all I turn up, in addition to Idaho,
is Madagascar and Tanzania. No obvious sites in India.

I don’t need an exhaustive list of star garnet localities worldwide, but:

Is there actually a locality in northern India? Where is that?
Is there any place worldwide, other than Idaho, where star garnets are
fairly common?

Thanks for any info,

Matt

Note: While I may send email outside of regular business hours, I do not
expect the same from others.

Dr. Matthew J. Kohn, University Distinguished Professor
Department of Geosciences, Boise State University
1910 University Dr.; MS1535
Boise, ID 83725-1535
mattkohn@boisestate.edu
https://www.boisestate.edu/earth/people/matthew-j-kohn/
fax: (208)-426-4061
Pronouns: He/him/his
China book:
https://www.amazon.com/dp/B0BRXWNTS6,
https://www.amazon.com/dp/B0BRZ2XRV9
Optical Mineralogy Book:
https://optical.minpet.org/
Petrology and Plate Tectonics Book:

https://global.oup.com/academic/product/petrology-and-plate-tectonics-9780190490645

MSA-talk mailing list -- msa-talk@minlists.org
To unsubscribe send an email to msa-talk-leave@minlists.org

Hi Matt et al., There are star garnets reported from quite a few localities worldwide. Most information is in the gemological literature. Other than Idaho, Madagascar is the place where star garnets seem to be the most widespread. The references below have photos of specimens and localities: - northern Idaho, USA (Guinel and Norton 2006 *Journal of Materials Science*) - the Phu Tho province of Vietnam (Tien and Nhan 2024 *Gem News International*) - the Singida region of Tanzania (Kammerling and Koivula 1990 *Journal of Gemmology*) - the Ambatondrazaka and Ihosy districts of Madagascar (Schmetzer et al. 2002 *Journal of Gemmology*) - and several unspecified localities in India (Schmetzer et al. 2002 *Journal of Gemmology*) The Indian localities seem to be poorly documented compared to the rest. I haven't seen the North Carolina locality Donna mentioned, but I'm also interested to hear if folks have information on it. Very cool. If you're interested in the other examples of oriented rutile needles in garnet, Keller and Ague (2020) has a compilation of the documented localities as of the time of publication. There have been several others documented since, and I know from personal communications that more are known but not published. (Ultra)high-pressure and (ultra)high-temperature groups both exist. Best, Duncan On Wed, Oct 8, 2025 at 6:42 AM Matt Kohn via MSA-talk <msa-talk@minlists.org> wrote: > Hi, > > I’m fact-checking some text for an Idaho Public Television science program > (for kids), and the question has come up: where do star garnets come from? > Obviously Idaho (it’s our state gem), but otherwise…? > > If you scan the internet, it says there are only 2 places worldwide: Idaho > and northern India. > > But, when I search on Google Scholar, all I turn up, in addition to Idaho, > is Madagascar and Tanzania. No obvious sites in India. > > I don’t need an exhaustive list of star garnet localities worldwide, but: > 1. Is there actually a locality in northern India? Where is that? > 2. Is there any place worldwide, other than Idaho, where star garnets are > fairly common? > > Thanks for any info, > > Matt > > Note: While I may send email outside of regular business hours, I do not > expect the same from others. > > ******************************************************************************************************************************* > Dr. Matthew J. Kohn, University Distinguished Professor > Department of Geosciences, Boise State University > 1910 University Dr.; MS1535 > Boise, ID 83725-1535 > mattkohn@boisestate.edu > https://www.boisestate.edu/earth/people/matthew-j-kohn/ > fax: (208)-426-4061 > Pronouns: He/him/his > China book: > https://www.amazon.com/dp/B0BRXWNTS6, > https://www.amazon.com/dp/B0BRZ2XRV9 > Optical Mineralogy Book: > https://optical.minpet.org/ > Petrology and Plate Tectonics Book: > > https://global.oup.com/academic/product/petrology-and-plate-tectonics-9780190490645 > > ******************************************************************************************************************************* > > _______________________________________________ > MSA-talk mailing list -- msa-talk@minlists.org > To unsubscribe send an email to msa-talk-leave@minlists.org >

GH

George Harlow

Thu, Oct 9, 2025 1:01 PM

Matt,
We have a small cabochon gem (4.6 ct) donated by a dealer from Sri Lanka. Unfortunately, he did not provide a locality. It is a cabochon displaying 4 rays. Dissanayake& Rupasinghe (1995) [Geologie en Mijn.bouw 74: 79- 88, 1995] notes gem garnet coming from the Elahera gem field in the high-grade metamorphics (Highlands/Southwest Complex).
Cheers,
George

George E. Harlow gharlow@amnh.org mailto:gharlow@amnh.org
Dept. Earth and Planetary Sciences
American Museum of Natural History
200 Central Park West, New York, NY 10024-5102 U.S.A.
Phone (212)769-5378 FAX (212)769-5533
WWW: http://www.amnh.org/our-research/staff-directory/george-e.-harlow
http://research.amnh.org/eps/jade/

From: Matt Kohn via MSA-talk msa-talk@minlists.org
Sent: Tuesday, October 7, 2025 5:10 PM
To: msa-talk@minlists.org
Subject: [MSA-talk] Localities other than Idaho with asterism in garnet?

EXTERNAL SENDER

Hi,

I'm fact-checking some text for an Idaho Public Television science program (for kids), and the question has come up: where do star garnets come from? Obviously Idaho (it's our state gem), but otherwise...?

If you scan the internet, it says there are only 2 places worldwide: Idaho and northern India.

But, when I search on Google Scholar, all I turn up, in addition to Idaho, is Madagascar and Tanzania. No obvious sites in India.

I don't need an exhaustive list of star garnet localities worldwide, but:

Is there actually a locality in northern India? Where is that?
Is there any place worldwide, other than Idaho, where star garnets are fairly common?

Thanks for any info,

Matt

Note: While I may send email outside of regular business hours, I do not expect the same from others.

Dr. Matthew J. Kohn, University Distinguished Professor
Department of Geosciences, Boise State University
1910 University Dr.; MS1535
Boise, ID 83725-1535
mattkohn@boisestate.edu mailto:mattkohn@boisestate.edu
https://www.boisestate.edu/earth/people/matthew-j-kohn/
fax: (208)-426-4061
Pronouns: He/him/his
China book:
https://www.amazon.com/dp/B0BRXWNTS6,
https://www.amazon.com/dp/B0BRZ2XRV9
Optical Mineralogy Book:
https://optical.minpet.org/
Petrology and Plate Tectonics Book:
https://global.oup.com/academic/product/petrology-and-plate-tectonics-9780190490645

Matt, We have a small cabochon gem (4.6 ct) donated by a dealer from Sri Lanka. Unfortunately, he did not provide a locality. It is a cabochon displaying 4 rays. Dissanayake& Rupasinghe (1995) [Geologie en Mijn.bouw 74: 79- 88, 1995] notes gem garnet coming from the Elahera gem field in the high-grade metamorphics (Highlands/Southwest Complex). Cheers, George George E. Harlow gharlow@amnh.org<mailto:gharlow@amnh.org> Dept. Earth and Planetary Sciences American Museum of Natural History 200 Central Park West, New York, NY 10024-5102 U.S.A. Phone (212)769-5378 FAX (212)769-5533 WWW: http://www.amnh.org/our-research/staff-directory/george-e.-harlow http://research.amnh.org/eps/jade/ From: Matt Kohn via MSA-talk <msa-talk@minlists.org> Sent: Tuesday, October 7, 2025 5:10 PM To: msa-talk@minlists.org Subject: [MSA-talk] Localities other than Idaho with asterism in garnet? EXTERNAL SENDER Hi, I'm fact-checking some text for an Idaho Public Television science program (for kids), and the question has come up: where do star garnets come from? Obviously Idaho (it's our state gem), but otherwise...? If you scan the internet, it says there are only 2 places worldwide: Idaho and northern India. But, when I search on Google Scholar, all I turn up, in addition to Idaho, is Madagascar and Tanzania. No obvious sites in India. I don't need an exhaustive list of star garnet localities worldwide, but: 1. Is there actually a locality in northern India? Where is that? 2. Is there any place worldwide, other than Idaho, where star garnets are fairly common? Thanks for any info, Matt Note: While I may send email outside of regular business hours, I do not expect the same from others. ******************************************************************************************************************************* Dr. Matthew J. Kohn, University Distinguished Professor Department of Geosciences, Boise State University 1910 University Dr.; MS1535 Boise, ID 83725-1535 mattkohn@boisestate.edu<mailto:mattkohn@boisestate.edu> https://www.boisestate.edu/earth/people/matthew-j-kohn/ fax: (208)-426-4061 Pronouns: He/him/his China book: https://www.amazon.com/dp/B0BRXWNTS6, https://www.amazon.com/dp/B0BRZ2XRV9 Optical Mineralogy Book: https://optical.minpet.org/ Petrology and Plate Tectonics Book: https://global.oup.com/academic/product/petrology-and-plate-tectonics-9780190490645 *******************************************************************************************************************************

CL

Cigdem Lule

Thu, Oct 9, 2025 6:25 PM

Dr. Kohn,

The most comprehensive book on Star Gems is written by Martin Steinbach of Germany. Although he is not an earth scientist, he is well known for his research on star gems for decades in gemological world.

I have attached scanned cover of the book and the star garnet locality table. Hope it helps.

Kind regards,
Cigdem

Çiğdem Lüle, PhD, FGA, GIA GG, DGA

Kybele LLC

825 E. Golf Road, Suite 1100

Arlington Heights, IL 60005

Tel: +1 847 848 6230

www.kybelellc.com http://www.kybelellc.com

From: George Harlow via MSA-talk msa-talk@minlists.org
Date: Thursday, October 9, 2025 at 10:38 AM
To: Matt Kohn mattkohn@boisestate.edu, msa-talk@minlists.org msa-talk@minlists.org
Subject: [MSA-talk] Re: Localities other than Idaho with asterism in garnet?

Matt,
We have a small cabochon gem (4.6 ct) donated by a dealer from Sri Lanka. Unfortunately, he did not provide a locality. It is a cabochon displaying 4 rays. Dissanayake& Rupasinghe (1995) [Geologie en Mijn.bouw 74: 79- 88, 1995] notes gem garnet coming from the Elahera gem field in the high-grade metamorphics (Highlands/Southwest Complex).
Cheers,
George

George E. Harlow gharlow@amnh.org mailto:gharlow@amnh.org
Dept. Earth and Planetary Sciences
American Museum of Natural History
200 Central Park West, New York, NY 10024-5102 U.S.A.
Phone (212)769-5378 FAX (212)769-5533
WWW: http://www.amnh.org/our-research/staff-directory/george-e.-harlow
http://research.amnh.org/eps/jade/

From: Matt Kohn via MSA-talk msa-talk@minlists.org
Sent: Tuesday, October 7, 2025 5:10 PM
To: msa-talk@minlists.org
Subject: [MSA-talk] Localities other than Idaho with asterism in garnet?

EXTERNAL SENDER

Hi,

I’m fact-checking some text for an Idaho Public Television science program (for kids), and the question has come up: where do star garnets come from? Obviously Idaho (it’s our state gem), but otherwise…?

If you scan the internet, it says there are only 2 places worldwide: Idaho and northern India.

But, when I search on Google Scholar, all I turn up, in addition to Idaho, is Madagascar and Tanzania. No obvious sites in India.

I don’t need an exhaustive list of star garnet localities worldwide, but:

Is there actually a locality in northern India? Where is that?
Is there any place worldwide, other than Idaho, where star garnets are fairly common?

Thanks for any info,

Matt

Note: While I may send email outside of regular business hours, I do not expect the same from others.

Dr. Matthew J. Kohn, University Distinguished Professor
Department of Geosciences, Boise State University
1910 University Dr.; MS1535
Boise, ID 83725-1535
mattkohn@boisestate.edu mailto:mattkohn@boisestate.edu
https://www.boisestate.edu/earth/people/matthew-j-kohn/
fax: (208)-426-4061
Pronouns: He/him/his
China book:
https://www.amazon.com/dp/B0BRXWNTS6,
https://www.amazon.com/dp/B0BRZ2XRV9
Optical Mineralogy Book:
https://optical.minpet.org/
Petrology and Plate Tectonics Book:
https://global.oup.com/academic/product/petrology-and-plate-tectonics-9780190490645

Dr. Kohn, The most comprehensive book on Star Gems is written by Martin Steinbach of Germany. Although he is not an earth scientist, he is well known for his research on star gems for decades in gemological world. I have attached scanned cover of the book and the star garnet locality table. Hope it helps. Kind regards, Cigdem Çiğdem Lüle, PhD, FGA, GIA GG, DGA Kybele LLC 825 E. Golf Road, Suite 1100 Arlington Heights, IL 60005 Tel: +1 847 848 6230 www.kybelellc.com<http://www.kybelellc.com> From: George Harlow via MSA-talk <msa-talk@minlists.org> Date: Thursday, October 9, 2025 at 10:38 AM To: Matt Kohn <mattkohn@boisestate.edu>, msa-talk@minlists.org <msa-talk@minlists.org> Subject: [MSA-talk] Re: Localities other than Idaho with asterism in garnet? Matt, We have a small cabochon gem (4.6 ct) donated by a dealer from Sri Lanka. Unfortunately, he did not provide a locality. It is a cabochon displaying 4 rays. Dissanayake& Rupasinghe (1995) [Geologie en Mijn.bouw 74: 79- 88, 1995] notes gem garnet coming from the Elahera gem field in the high-grade metamorphics (Highlands/Southwest Complex). Cheers, George George E. Harlow gharlow@amnh.org<mailto:gharlow@amnh.org> Dept. Earth and Planetary Sciences American Museum of Natural History 200 Central Park West, New York, NY 10024-5102 U.S.A. Phone (212)769-5378 FAX (212)769-5533 WWW: http://www.amnh.org/our-research/staff-directory/george-e.-harlow http://research.amnh.org/eps/jade/ From: Matt Kohn via MSA-talk <msa-talk@minlists.org> Sent: Tuesday, October 7, 2025 5:10 PM To: msa-talk@minlists.org Subject: [MSA-talk] Localities other than Idaho with asterism in garnet? EXTERNAL SENDER Hi, I’m fact-checking some text for an Idaho Public Television science program (for kids), and the question has come up: where do star garnets come from? Obviously Idaho (it’s our state gem), but otherwise…? If you scan the internet, it says there are only 2 places worldwide: Idaho and northern India. But, when I search on Google Scholar, all I turn up, in addition to Idaho, is Madagascar and Tanzania. No obvious sites in India. I don’t need an exhaustive list of star garnet localities worldwide, but: 1. Is there actually a locality in northern India? Where is that? 2. Is there any place worldwide, other than Idaho, where star garnets are fairly common? Thanks for any info, Matt Note: While I may send email outside of regular business hours, I do not expect the same from others. ******************************************************************************************************************************* Dr. Matthew J. Kohn, University Distinguished Professor Department of Geosciences, Boise State University 1910 University Dr.; MS1535 Boise, ID 83725-1535 mattkohn@boisestate.edu<mailto:mattkohn@boisestate.edu> https://www.boisestate.edu/earth/people/matthew-j-kohn/ fax: (208)-426-4061 Pronouns: He/him/his China book: https://www.amazon.com/dp/B0BRXWNTS6, https://www.amazon.com/dp/B0BRZ2XRV9 Optical Mineralogy Book: https://optical.minpet.org/ Petrology and Plate Tectonics Book: https://global.oup.com/academic/product/petrology-and-plate-tectonics-9780190490645 *******************************************************************************************************************************