Tag: geology

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Rhodochrosite is Spotlight of In-Person Program Meeting; Tuesday, May 17th, 7:00 p.m.



The story of the Sweet Home Mine from its beginnings as a modest 1870’s silver mine to its rebirth as a world-renowned source of beautiful red rhodochrosite crystals will be featured in this month’s program. We will view Part 1 of a video illustrating the accidental discovery of one of our nation’s most impressive sources of this beautiful gemstone.

This program meeting is at 7:00 p.m. Tuesday, May 17 and will be held IN PERSON. Check out our Meetings page to get directions and further info about the location.

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In-Person Program Meeting April 19, 2022, 6:30 PM

We are having our first in-person program meeting in over a year! PLS member Janie Duncan will provide a presentation on the History of Beads Tuesday night, April 19, and members are looking forward to seeing each other in the flesh for a change, instead of virtually. Check out our Meetings page to get directions and further info about the location. We are VERY excited!

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Gem Pegmatites of Southern California Subject of March 15 Virtual Program Meeting with Walt Lombardo

Zoom Meeting starts at 7:00 p.m., Tuesday, March 15, 2022

Walt Lombardo, Owner & Founder of Nevada Mineral & Book Co., located in Orange, Calif.

Southern California is known worldwide for the production of gemstones and mineral specimens from the granite pegmatites in San Diego, Riverside & San Bernardino counties. Some of the more well-known gem minerals are Tourmaline, Garnet, Aquamarine, Morganite, Kunzite, Quartz, Topaz and Lepidolite. Most notable are the Pala and Mesa Grande mining districts, which supplied beautiful tourmalines to the last Dowager Empress of China in the early 1900’s, and continue to produce world-class gems and mineral specimens today. Our program speaker this month is Walt Lombardo, a geologist with over 35 years experience related to mining and mineral exploration. Walt’s talk will include discussion of the regional geology which made these deposits possible, history of mining in Southern California, some of the more important mines, and the gem minerals that they produced.

Meeting starts at 7:00 p.m. If you’d like to join us, write marcia.pls.emails [at] gmail [dot] com to request a Zoom link.

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PLS Explores “The Inner Beauty of Caves” by Mary Pat Weber

Program Meeting, Tuesday, February 15, 2022; 7:00 pm via Zoom.

Photo courtesy of Mary Pat Weber

A cave is more than just a hole in the ground.  These spectacular creations are natural laboratories for preserving fossils, recording past climate, and providing habitats for unique and rare animals.  Due to their global importance physically, culturally, and ecologically, 2021 was designated the International Year of Caves and Karst. As a geologist, Mary Pat finds caves fascinating and takes every opportunity to tour them.  Join us Tuesday night to explore this intriguing subterranean world that includes some of the major show caves of the Western U.S. You can leave your high boots and flashlights at home – this meeting’s virtual!

Meeting starts at 7:00 p.m. If you’d like to join us, write marcia.pls.emails [at] gmail [dot] com to request a Zoom link.

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January 18 Virtual Program Meeting Explores Crystals

Pictured above: Actinolite, Quartz point, Axinite. Can you identify the other four?
Photo credit: PLS member Elizabeth Weston

Our Tuesday, January 18, 2022 Program Meeting will be held via Zoom. PLS member David Lacy will provide the evening’s presentation as an overview of Crystals and Crystal Forms.  We will look at the differences between geometrical (ideal) crystal forms and some of the crystal habits in nature, where geometric forms meet the real world.  We will check on just what are the characteristics of a crystal, what is a crystal habit, symmetry in crystals, and the seven crystal systems met in nature.  Some mineral specimens will be visually shared to demonstrate real-world crystal habits. Meeting starts at 7:00 p.m. If you’d like to join us, write marcia.pls.emails [at] gmail [dot] com to request a Zoom link.

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The Tunnel to Nowhere

December’s educational field trip will be at 8AM on Saturday, December 18th to Shoemaker Canyon Road above Azusa.  We’ll be visiting the Tunnels to Nowhere, which were hewn out of solid granite in 1969.  These tunnels were built to provide an escape route out of LA in case of nuclear attack.  Now they sit vacant; a lone sentinel to times forgotten. 

This trip is suitable for any passenger car and is 31 miles from Pasadena.  The walk to tunnel is 2 miles with an elevation gain of 700 feet.   We’ll be on the lookout for various ores and minerals, but this is more an educational/nature walk rather than a collecting trip.  For more details, please contact Rex at rexch8@yahoo.com 

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Tuesday, Nov. 16 Virtual Program Meeting Explores the Chixculub Impact Event with Paolo Sanchez; 7:00 p.m.

Pasadena Lapidary Society’s very own future geologist/geophysicist, Paolo Sanchez, will present “Traces of Extinction: The Search for Rocks and Minerals at Chixculub” for our November program meeting. For those wondering what the heck ‘Chixculub Impact Event’ is, think meteor meets dinosaurs. Paolo will present his current ongoing research examining tektites derived from Chixculub and what their respective chemistries tell us about the minerals and lithologies associated with the impact event, with the potential of understanding the lithology of the meteor itself.

Earlier this year, Paolo was awarded the California Federation of Mineralogical Societies’ (CFMS) Robert O. Deidrich Memorial Fund Scholarship for school year 2020-21. He’s been studying geosciences at UC Berkeley, working his way up to a PhD and possibly obtaining a career as a professional researcher.

There will be no Rock of the Month discussion for this meeting.

The Tuesday, Nov. 16 program meeting starts at 7:00 p.m. via Zoom. To join us, send an email to (new email address!)… marcia.pls.emails[at]gmail.com in advance, using ‘PROGRAM MEETING’ in subject line, and request the Zoom meeting link. We’re looking forward to seeing Paolo – and hope to see you virtually as well!

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Tuesday, Oct. 19 Virtual Program Meeting Focuses on Urban Rockhounding in Tucson; 7:00 p.m.

Among some of our favorite rockhound travel guides are Dick and Mary Pat Weber. For the Tuesday, October 19 presentation, Mary Pat will take us on a Practical Guide to Urban Rockhounding in Tucson.

In a few months dealers, buyers, and collectors will gather together for the largest rockhound  event in the world.  You will find great bargains relating to all aspects of our hobby offered by vendors from all corners of the globe.  If you can’t find it in Tucson, it probably doesn’t exist anywhere.  According to Mary Pat, you will run out of money long before you cross off all the items on your wish list.

With over forty shows from which to choose, it can be a bit confusing for the first-timer.  Mary Pat will offer practical advice for navigating though the “Tucson experience” to make it both efficient and fun.  This program is jammed packed with photo highlights of the biggest club show in the world, including specimens from world class museums such as the Smithsonian and other private collections. If you’ve been thinking about visiting Tucson for the rockhound shows but have yet to, here’s a chance to see what they’re all about.

PLS member Mona Ross will provide October’s Rock of the Month talk on one of the world’s rarest gemstones, Grandidierite.

The Tuesday, Oct. 19 program meeting starts at 7:00 p.m. via Zoom. To join us, send an email to joenmar1[at]verizon.net in advance, using ‘PROGRAM MEETING’ in subject line, and request the Zoom meeting link. Hope to “see” you there!

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September 18 Field Trip to Palos Verdes for Agate and Glaucophane

Boy, is it hot outside! Nothing beats summertime rock collecting at the beach!

CHANGE IN DEPARTURE TIME! Our next trip will be at 10AM to Palos Verdes on Saturday, September 18th, 2021 to collect striped root beer agates, yellow agates, and bluish green glaucophane. For more information, please contact Sue D at: apple_pis@yahoo.com

Yellow Green Agate from Palos Verdes
Glaucophane from Palos Verdes

Pics above of striped root beer agate, yellow green agate, and glaucophane were provided by PLS member Rex N.

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Caltech Professor George Rossman takes a look at Chinese Andesine Feldspar for Tuesday, Sept. 21 Zoom Program Meeting

A variety of faceted andesines in table-down orientation.

There’s a controversy brewing over a new and beautiful red transparent gem out of the Democratic Republic of the Congo as well as Tibet or an unspecified location in China. Caltech Professor of Mineralogy George Rossman will discuss his research on this red copper-carrying feldspar at our September program meeting.

The Tuesday, Sept. 21 program meeting starts at 6:30 p.m. via Zoom. To join us, send an email to joenmar1[at]verizon.net in advance, using ‘PROGRAM MEETING’ in subject line, and request the Zoom meeting link. “See” you there!

Image borrowed from: http://minerals.gps.caltech.edu/manuscripts/2011/Chinese_Red_Feldspar_I/Index.html