Event Report- 2014 Castro Valley Club-Newark Pavillion Show, Newark, CA (Feb 21-23)

Gem Green Tourmaline from China

A Visit to the Castro Valley Mineral Club Show, 2014

By Jeremy Zolan – Earth Surgery

The Mineral and Gem Society of Castro Valley puts on an excellent small mineral show each year at the Newark Pavillion in Newark, CA. This small locally focused show great for all audiences and ages, and makes for a wonderful weekend outing especially with family and friends! This show attracts dealers who offer an extremely wide array of material ranging from gem and lapidary rough to rare minerals. There are also many displays and booths offering activities, information, and many other things in addition to those who strictly sell specimens. During my visit, everyone at this show was extremely kind and made me feel welcome to the California collecting scene which I am extremely new to. For new residents of California looking to make connections, this is a great springboard into the scene.

I have recently been staying in the the Barstow area of Southern California so getting to this show was quite a drive. It did allow me a first glimpse at the landscape of many interesting places I have never visited before and was very scenic. Here we have a picture of high desert scrub in Boron, CA with the titanic US Borax Mine lurking barely visibly in the distance. Many of the hills in the photo are partially made from giant tailings piles. This mine is not only famous for its incredible size and high production but for its mineralogy which is highly distinctive. In addition to producing many thousands of fine colemanite specimens, it also is well known for splendid examples of many rare borates such as inyoite, kurnakovite, probertite, and kernite.

Scrub Desert on the way to a gem show in california

Scrub Desert on the way to a gem show in california

The first thing I did when I arrived at the show was check out the display cases, which there were many of for a small local event. In my home New England region, events of similar size only rarely have as many displays so I was pretty surprised. The cases were filled by a local crowd including both collectors and museums but definitely far more of the former rather than the latter. Lapidary, mineralogy, paleontology, and anthropological themes were all present in the displays however there was a significant bias towards the lapidary side of things with comparatively very few mineral display cases. This was somewhat reflected in the abundance of lapidary dealers at the show though there were also many great mineral and fossil dealers as well.

Morgan Hill Poppy Jasper on Display

Benitoite and Neptunite Specimens on Display

Cabochons on Display by Mark Montgomery at the 2014 Castro Valley Show

Fremont California in the Pleistocene Era

Specimen of Columbian Mammoth from San Francisco

Next off, I decided to parouse the dealer booths and was pleased with the great variety in not only species and localities but prices I saw. There were many great specimens to be had for under fifty dollars including many lots of old material at multiple dealers that appeared to have not been repriced in decades. There was truly something for everyone at this event.

The first dealer I visited was The Uncarved Block which always has a good assortment of material though tends to mostly focus on classic, well known species that display best in the thumbnail to cabinet range. Many specimens stuck out to me but those pictured below were my favorite, most of which are things that rarely turn up on the West Coast.

First off we have two teal kyanite crystals in a biotite schist matrix from the Harts Range in the Northern Territory, Australia. The color indicates that the specimen may more precisely be from Huckitta Well or nearby. The crystals were aesthetically skewered through the matrix and had a very pleasing deep aqua blue color. The longest was exposed to about 6cm of its total length. The Harts Range is one of only a very small assortment of localities in Australia that produce gem pegmatite minerals such as beryl and garnets.

Kyanite Crystals in Biotite Matrix from Australia

Next, I spotted this specimen of beryl from Slocum’s Quarry in East Hampton, Connecticut. This very uncommon, very old, and now very closed locality is well known for its yellow beryl var. heliodor crystals which were opaque to extremely gemmy and sometimes formed in pockets. The pocket crystals were often etched in a manner similar to the Ukranian crystals from Volodarsk-Volinskiithough their color saturation ranges to an extremely deep and gorgeous pumpkin orange color. Slocum’s Quarry also exhibits an impressive suite of rare Be, Nb/Ta, and REE minerals. Ernie Schlicter collected the below piece which has bigger crystals than most by far even though they are of a very light color for Slocum’s.

Beryl in Quartz from Slocum Quarry, East Hampton, Connecticut

Romanian amethyst from Porkura, Huneodoara Co. is something I am always looking out for and in my opinion, are some of the world’s great amethysts with their extremely deep color saturation and unusual crystal shapes. They strongly resemble newer specimens from Guerrero, Mexico but being the snob that I am, I think the Romanian specimens always have better color. I really loved this piece which has the perfect balance of purple cityscape-like crystals and contrasting matrix. Truly a fine amethyst.

Purple Amethyst Crystals from Romania

Finally, I spotted this set of alphabet agate from Indonesia. The letters are formed by natural tubular inclusions of iron oxides and clays in the agate. These sets always amaze me. Imagine how many thousands of pieces must be sorted through to get a full alphabet! Truly a daunting task, it has been said to take years to find a full set by inspecting rough. Some letters such as R and Q with unusual shapes are apparently rarer than others.

Agate Alphabet Cab Set

It was then over to Earth’s Treasures, run by avid field collector Rick Kennedy. Rick has been working the California Blue Mine in San Bernardino County for aquamarine, topaz, quartzes, wodginite, and other associated species. This locality is outside of what is traditionally regarded as the Southern California Pegmatite district so I had to know more considering it could change our perception of pegmatite mineralogy in California. It appears that this pegmatite is of intermediate elemental distribution (LCT/YNF) though it is likely very lithium poor unlike some geochemically similar envirtonments though the micas would need to be analyzed to truly validate that statement. Greisenization took place in the top of the peg and created a lot of topaz and fluorite mineralization while deeper in were the nice gemmy aquas. Some of the crystals show interesting tapering that reminds me of specimens from Brazil and Argentina. Below is my favorite crystal from the locality he had for sale at his booth.

Aquamarine from the California Blue Mine

Rick had lots of other great material too; a lot of exotics especially. This limonite after magnetite pseudo is very peculiar especially. Considering Kansas is mostly sedimentary, one would not expect to see magnetite originating from there. Many of these magnetites were collected around 100 years ago.

Limonite after Magnetite Psuedomorph from Kansas

John Garsow had a lot of great material too with a focus on gem minerals, rough, and materials. John is also an avid field collector who has made some really nice finds in Southern California. He had this Chinese tourmaline that immediately caught my attention. If there is one group of minerals that China lacks it is pegmatite minerals. There are only two very poorly explored main areas for specimen producing gem lithium pegmatites in China; near Kashi, Xinjiang Uygur Province or the Gaoligongshan ranges in Yunnan Province. Both are located in notoriously remote and culturally distinct regions in western China. This piece, measuring in at around 8cm tall is from the latter which is known for mostly producing only tiny crystals to 2 or 3cm. Chinese specimens show frequent mislabeling so it is possible this is from another entirely different area since it does not resemble the majority of specimens I’ve seen from either Xinjiang or Yunnan Provinces. I thought it was a really fascinating piece for that reason.

Gem Green Tourmaline from China

Taking a break from strictly minerals, I decided to check out the Northern California Geological Society’s booth to ask some questions about local geology since I am by no means well versed in the geology of California which is extremely different from those good old passive margins on the East Coast that I’ve explored and collected in so much. Mostly, I was curious about the formation, petrology, and mineralogy of blueschists and eclogites; rare, extremely high grade metamorphic rocks I was rewarded with kindness and a very thorough explanation. NCGS offers many excellent field trip publications exploring many themes in the northern California area. They also have an excellent scholarship program for B.S through Ph.D.-level students in California and the adjacent states.

Origin of Ophiolite and Franciscan Complexes

Geologic Cross Section of Mt. Diablo

Glaucophane Schist from the Franciscan Formation in Marin County

Alfredo Petrov has long been one of my favorite mineral dealers for the scientific focus of his merchandise. In addition to specimens of many truly weird minerals, he often has specimens of odd reagents or elements. He had several vials and containers of selenium, calcium, lithium, and samarium. I encourage the sale of element samples at mineral shows. Element collecting was quite popular a few years back but seems to have tapered slightly at least in the US. As for minerals, hw of course had a lot of oddball specimens..in fact too much to mention. Some of my favorites were his tiny sapphires panned from Japanese alluvial gravels, analcime and natrolite with celadonite from East Greenland- far away from the famous mineral producing regions on the frigid island. I thought one of the nicer high end pieces he had was this English torbernite. It is priced very competitively considering the quality of the specimen, high pedigree A.E. Foote label, and overall rarity of the material.

Torbernite from Cornwall, England

I have been a customer of Mineralogical Research Corporation (Minresco) in the past so it was great visiting their booth and looking through some of their flats in person. They had lots of fine quality, well known material from worldwide locations displayed in the front of the booth and rarer specimens behind. As for the material out front, I thought their specimens of the new azurite find from Lavrion, Greece were some of the better I have seen. I did however spend most of my time looking at the rare material in the back flats which was perhaps the most varied material in the entire show. I will refrain from mentioning my favorites because there were just simply too many. I did think this vial of szabelyite from Bou Azzer Morocco was pretty cool considering it was probably collected and studied far before the mine produced the specimens it is currently famous for. It may likely be one of the earliest collected mineral specimens from Morocco in circulation. That may not be saying much though considering that the vast majority of Moroccan pieces are no more than 20 years old. I still thought it was very interesting to see.

Szaibelyite from Bou Azzer, Morocco

Uranium Minerals for sale at the Mineral Show

The 2014 Castro Valley Show was great fun and it was definitely geared to a wider audience than I feel most smaller local mineral shows tend to target. Not only was there great diversity of material available, but amazing deals to be had. Not only is this a great show for everyone interested in minerals as a hobby, but would be rewarding for dealers looking to obtain inexpensive, high quality material for their inventory. As far as improvements, my only big criticisms were that I wish the displays had better labeling and there was more emphasis on local field collecting in them. I cannot say the show had any other drawbacks for me considering its nature and size. I thought it was awesome!!! This is a great event that I hope continues to be held for many years in the future!

Below is a specimen purchased at the Show which is available from Earth Surgery – Contact at JZolanSci@gmail.com to inquire.

Uranopilite- Happy Jack Mine, Utah Ex. Dr. Eugene B. Gross PRICE: $

Uranopilite Glowing under UV Light

Uranopilite- $100
(UO2)6(SO4)O2(OH)6·14H2O
Happy Jack Mine, White Canyon Dist., San Juan Co., UT
Ex. Dr. Eugene B. Gross
6.7 x 2.4cm 21.81g

email JZolanSci@gmail.com to order

The rare uranium secondary uranopilite is rarely available in specimens as rich as this one where it is present as bright highlighter-yellow powdery masses in a dark sedimentary matrix. The uranopilite masses may be poorly defined crystals. Typical of most uranyl minerals, the specimen is vividly fluorescent in all UV wavelengths and slightly radioactive. The identity of this specimen is highly credible- this specimen resided in the personal collection of Dr. Eugene B. Gross; a geochemist who prospected the uranium deposits of Utah for the Atomic Energy Commission.

Uranopilite has a very odd structure in that it is a polymer composed of metal oxo-clusters linked by sulfate “couplings.” This phenomenon of uranyl-clustering is observed in a select few uranyl species and have some structural characteristics of formal polyoxometallates, which of only one occurs in nature. If you wish to inform yourself more on the cluster chemistry of they uranyl cation, especially in minerals, I recommend this paper: http://minmag.geoscienceworld.org/content/75/1/1/F3.expansion.html

To search for minerals for sale that were mined in California, check out this search for minerals of California on eBay

2013 Gilsum Rock and Mineral Show Report

Gilsum New Hampshire Mineral Show

Show Report: 49th Annual Gilsum Rock Swap

by Jeremy Zolan – http://earthsurgery.tumblr.com

The Gilsum Rock Swap- http://www.gilsum.org/rockswap is one of the more popular New England mineral shows and is held in the rural town of Gilsum. New Hampshire. Gilsum is at the heart of an area very rich in pegmatites, many formerly mined for mica and beryl. New Hampshire has many great and diverse mineral localities. It is well known for its pegmatites which are both numerous and mineralized in rare species including several type localities most numerously found at the Palermo No. 1 Mine http://www.mindat.org/loc-3942.html. The miarolytic granites in the White Mountains region have produced many large, well crystallized pocket specimens of smoky quartz, amethyst, microcline, topaz, and rarer minerals such as arfvedsonite and danalite. Low temperature hydrothermal veins in the southwest corner of the state have produced fine fluorite crystals of a deep apple green color, notably from the William Wise mine- http://www.mindat.org/loc-4521.html.The Gilsum Rock Swap is an awesome way to celebrate the amazing mineralogy that New Hampshire has to offer.

In addition to being one of the few outdoor mineral shows in the region, a very large percentage of the material offered by vendors attending has been found locally. It’s also a great opportunity to catch up with field collectors and learn about recent finds and new localities. Swapping is encouraged at this show, so people often show up with their own personal finds to show off and trade. There were also two talks by Steve Garza on prospecting for mineral specimens and one by Bill Petronis on how to find Herkimer diamonds. I think it is great that the focus of the presentations is teaching practical skills in finding mineral specimens. The Gilsum Rock Swap is one of my favorite mineral shows and is still going strong after it’s 49th year.

This year’s Gilsum Swap was the first mineral show I attended as a dealer, however I did also take much time to look around and talk to local collectors. I am always amazed at the abundance of fine, local material available for unbeatable prices at this show; proof of that was the stock of Tom Minnich. Tom is an avid field collector and member of the Keene Mineral Club. He has collected many fine specimens throughouth New England, New York, and Nova Scotia.


A nice quartz cluster from Chesterfield Hill, Keene, Cheshire Co., New Hampshire. Specimens from here aren’t well known but quite nice. Some pretty big scepter quartzes have been collected from this near monomineralic vuggy low temperature hydrothermal quartz vein deposit in Clough quartzite. Tom is the guy to go to for these specimens.


Another nice quartz specimen from Diamond Ledge, Stafford, Connecticut. I really loved the aesthetics of this piece.


Tom also had this great large cabinet specimen from the now closed Green’s Farm Garnet Mine in Southbury/Roxbury Connecticut. Here’s a closeup view. This past year the property received a new land owner that does not approve of collecting in the mine. It’s a real loss for Connecticut’s mineral heritage- this used to be THE PLACE for taking people just getting into mineral collecting considering the abundance of well formed garnets at the locality.


There weren’t many new local finds from New Hampshire at the Gilsum Swap but Patrick Bigos from Midnight Minerals (http://midnightminerals.com/) had large, vibrant yellow fluorescing pieces of fluorescent manganapatite from the Ham and Weeks Quarry in Wakefield, NH. Yellow fluorescing manganapatite is found in many New England pegmatites but these specimens from Ham and Weeks are very large and brightly fluorescent.


A rare chance to get your own seventeen year cicada!


Here’s a specimen of beryl from an odd locality- Cucumber, Maine!! Robert Batic had bits and pieces from several old local collections at the show featuring many interesting locality pieces and some old classics too.


Mr. Batic also had this huge actinolite specimen from the Carlton Talc Mine in Chester, VT. Some big crystals on this one!


Friends from Mindat Linda and Don Kauffman of Lindon Mineralogy had a lot of esoteric New England material. Of particular note was this small well-formed triphylite crystal from the G.E. Smith Quarry in Newport, NH.


Rocko Minerals had quite a few awesome Herkimer diamonds with calcite, dolomite, and pyrite from the Benchmark Quarry. These came from an old and very fine collection of Herkimer material. This locality formerly produced amazing Herk combination specimens but is now totally off limits to collecting. It’s tragic that amazing pieces like this are now just tossed into the rock crusher!


Rocko also had this huge baryte crystal with pyrite from the Niobec Mine in Quebec- this carbonatite hosted niobium mine is famous for giant crystals of baryte. This is a pretty good one.


My former mineralogy and petrology professor Dr. Peter Nielsen of Keene State College showed me this wonderful scepter topaz from the Kandahar Mine in Braldu, Pakistan

Dr. Nielsen knows that I enjoy unusual specimens more than anything else, so he showed me these two great specimens of Heulandite-Ca from the type locality of Torch Hills, Scotland. I’ve never seen specimens from this locality in person! Apparently they were collected within a day’s time from the base of a dam when the water levels were unusually low.


D. Robinson Minerals usually has amazing things from unusual localities. My favorite that he had were his Korean specimens. Here’s a schorl that was collected right outside of Pyongyang before the Korean War.


The Pamir Mountains in Tajikistan have some rich pegmatites that unfortunately don’t produce many specimens. This tiny rubellite with a foitite (not proven but likely) cap show the kind of potential the region has.


Doug also showed me this Yaogangxian piece that featured both twinned bournonite and twinned fluorite crystals!


Wayne Corwin of Toveco is an avid Mindat member and always a familiar attendee of the Gilsum Swap. Wayne mines the Tripp Mine in Alstead, New Hampshire for aquamarine specimens and gem rough. He also encounters specimens of other material such as almandine garnets and schorl at this mine. He showed me some especially large trapezohedral almandines in matrix.


Jim Tovey of Toveco had several specimens of amethyst from Hopkinton, Rhode Island at his booth. This large cabinet specimen was probably the best of them


The 49th Annual Gilsum Rock Swap was yet again a great event! Although it was not as busy as it has been in previous years, it was still a lot of fun. Some pros: strong emphasis on locally sourced material and a great place to talk to other collectors to learn about New England mineralogy and mineral collecting. Quaint, peaceful setting in a small New England town. Cons: There were no booths primarily focused on swapping despite the name. In previous years, the show sponsored collecting trips to local pegmatite mines. Now unfortunately, most if not all the pegmatite mines in the vicinity of Gilsum are technically off limits to mineral collecting. You can buy maps to many of these localities at the show but you can’t actually visit most of them. I’d like to see accessibility to these localities change in the future. Celebrating the local pegmatite mines is the reason why there is a mineral show in Gilsum, after all.


On my way home to Connecticut, my collecting partner Mike, and I found a new locality for titanite crystals at a large construction site near Waterbury, CT. Above you can see many orange brown titanites to 4cm in a coarse grained amphibolite matrix. They were also granules of purple fluorescent scapolite associated with the titanite. I just thought I’d throw this picture into the report because it was such an interesting find!

Here at Wheretofindrocks.com, we encourage all of our visitors to visit a local rock show! You can be sure, there is one around your area at some point in the year! Check out the BEST Rock and Gem Calendar online on The-Vug.com