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Delvers Gem & Mineral Society, Inc. - mailing address: P.O. BOX 112, Wilmington, CA. 90748
DELVINGS The Newsletter of the Delvers Gem & Mineral Society
Volume 72 Number 2 February 2019
Hungarian Opal Jewelry, Budapest 1881 (Imperial Treasury, Vienna)
OPAL – by Fred Dexling
Opal is a precious gemstone of non-crystalline structure that can have a brilliant play of
color. It is heat sensitive and somewhat soft.
A Very Short History of Opal
For me the history of opal starts with the Hungarian opals privately mined and then
taken over by the Slovakian Government in 1788 – that event killed the opal mining.
The Australian opal mines started producing around the 1900’s and became the largest
source of opal for the next century. As with any deposit the Australian mines have become
depleted. I have only seen minor quantities from Coober Pedy.
C o n t i n u e d o n p a g e 5
From Fl icker, courtesy of Kotomi
DELVINGS February 2019 Page 2
Taps from the Gavel
Hello to all. I hope every one of you made it through the Holiday season in one piece. I spent a little
time to reflect on the last year and as many do and I began to put that list together of things I want to
change about myself in the year to come.
That became a little difficult. Personal reflection can get deep at times and this became one of those
moments for me. Where should I start? Ah, I thought I will lose some weight. Do I drink too much?
No!! Ok I can clean up my shop and keep it organized.
As the list grew and grew and grew, I found there were too many improvements to work on. Maybe
this wasn't such a good plan. Then I decided to take another approach to this Idea. Could I pick one
thing and devote all of my efforts to that one thing. Yes that was going to be the plan.
What was it to be? I wondered if I was wise enough to pick the most important part of my life that I
need improvement on. Then it came to me. And I thought if I could remember to do this every day
that I could help make the world a better place. It was so simple.
I simply would remember to live every day with this thought in my head. Always be open to new ideas
and treat all in the way that I would like to be treated. I hope we all can find those improvements, no
matter how small, that will help make the coming year better than the last.
HAPPY NEW YEAR TO ALL - Peter German, President
Minutes of the January 11th Board/General Meetings – Teresa Taylor
Andrew will write a check for the 2019 rent of the Delvers meeting room. Susan Parish is taking on the
role of Treasurer and is eager to arrange a meeting at the bank for transferring account authorizations.
The keys for the bathroom were gone and the parking lot lights were not on so this led to some
confusion at the beginning of the meeting; Andrew said he would enquire about these issues. Currently
our bank balance is at $9,241.52 cents. President Pete German will appoint a new federation director.
We need several members willing to perform the annual audit of our books. Fred Dexling brought
printed-out material he wrote about rock hound collecting locations near quartzite. He also brought
talked about opals from around the world, and brought specimens, and handouts. Dale displayed some
very rare mineral samples. 19 members and one guest were present.
Please remember to pay your 2019 club dues
At our meeting, or by mail to our treasurer:
Susan Parrish PO Box 59716
Norwalk, CA 90652
Individual- $15, two adults at the same address - $25
DELVINGS February 2019 Page 3
FIELD TRIPS
Feb 16-18, Ludlow, Searchers G&MS. Meet at Dairy Queen 9 AM. Contact Jimmy, 714-904-8573
Feb 17, Tajiguas Beach, Ventura G&MS. 9 AM-2 PM. Contact Luther Brown, [email protected].
Feb 23-?, Hauser Geode Beds, Yucaipa G&MS. Contact Dennis Gibbs, 909-338-0413
March 23, Castle Butte, Ventura county clubs. Meet in Mojave, 8 AM.
ROCK AND GEM CLUB SHOWS
March 2 - 3: VENTURA Ventura Gem & Mineral Society Ventura County Fairgrounds 10 West Harbor Blvd. Hours: Sat 10 - 5; Sun 10 - 4 http://vgms.org/category/gem-show/ March 8-10: POMONA CFMS SHOW & CONVENTION Los Angeles County Fairgrounds There is a charge for admission and for parking Tickets can be purchased online in advance https://pasadenalapidary.org/2019-show
March 8-10: Stoddard Wells Tailgate Victor Valley Gem & Mineral Club 9-5 Daily (Field Trip Saturday at 9 AM) Vendor spaces are free, first-come first-served https://vvgmc.org/tailgate.html March 30 - 31: TORRANCE, CA South Bay Lapidary & Mineral Society Ken Miller Recreation Center, 3341 Torrance Blvd (entrance on Madrona Ave) Hours: Sat. 10 - 5; Sun. 10 - 4 https://southbaylapidaryandmineralsociety.com/annual-rock-show
Brad’s Bench Tips
PROTECTING FINISHED SURFACES
I figure that any accidental scratch I make on a piece means
about 15 minutes of extra sanding and polishing. So after
finishing major surfaces I typically cover them with some
masking tape to avoid any scratches when doing final work
like cleanups and setting of stones. The blue masking tape
used by painters’ works particularly well, because it doesn't
leave a sticky residue.
PICKLE PRECAUTIONS
A hot pickle pot gives off fumes that bother me in my home workshop. I get around that by using my pickle
cold. I mix it a little stronger than for a hot pot so that it works almost as quickly. I keep it in a large-mouth
plastic bottle and cap it off whenever I'm done using it.
Be more Productive with Brad's "How to Do It" Books, http://amazon.com/author/bradfordsmith
Delvers Gem & Mineral Society, Inc. - mailing address: P.O. BOX 112, Wilmington, CA. 90748
Faceting Cut of the Month:
Hexastarcircle
From the San Diego Gem & Mineral Society’s newsletter, The Pegmatite, October 2018, reprinted with permission of author Bill Brisbois and SDGMS editor Lisbet Thoresen.
SDMG Faceting Instructor Bill Brisebois not only is a prize winning facetor, but also is a designer of his own facet diagrams. Bill likes to share his creations with the rest of the faceting community, and we all gain much from his knowledge and abilities. We have his permission to publish his diagrams. Download this diagram from the SDMG website at:
http://www.sdmg.org/pdf/Brisebois_facet_diagram_2018-09.pdf
This cut makes it look like there
are thousands of lines in it. Very
interesting hexagon cut with
mix symmetry. Works very well
in quartz. Beryl is an ideal
material for this cut.
I should have added some cutting notes in that this is a very challenging cut! You will notice that between
P1 and P3 there is less than a degree of difference and when I scaled this for lower R.I. material, for some
reason this is what GemCad came up with. I have been test cutting this and it CAN be done, however, it is
very hard to see the difference and I recommend polishing P1 first and then cutting in P3 with a fine grit
lap so it can be seen easier. Also, for the pre-polishing and final polish, I would use a very hard lap like a
Diamatrix with 50-100k diamond. Your machine should be well-tuned and runout minimal.
Also, you could scale P1 up and P3 down (for a difference of 2+ degrees) and will have a little different
effect, but it will still have the same overall look. This may make P2 smaller and not meet at tips of P3 and
meet at P4, but it doesn’t have to! Another note: P7 can be confusing for a newer faceter and note that 93-
3, only cut into P6 to make the “circle” and that 5-11, etc. will form the “flower petals” and cut through P5
to touch/meet P4.
Hopefully, this will help as I would love to see what others come up with and variations they create of this!
DELVINGS February 2019 Page 5
Opal from Shewa Province, Ethiopia. Wikimedia, courtesy Lech Darski
Rough Welo Opal from Wollo Province, Ethiopia
Wikimedia, courtesy Dpulitzer
Continued From Page 1:
Opal - by Fred Dexling
Around 2000 I saw opal rough from
Ethiopia. What was offered was
brown body color with a play of
color. It was from the Shewa
Province. I was to discover the opal
was extremely unstable. The opal
extensively cracked as I was fine
grinding.
Around 2017 I saw opal rough with
exciting play of colors in a clear body
color from the Welo area of Ethiopia.
It seems to be stable. The area might
become a major opal source for
some time.
My Opinions on Buying Ethiopian Opal
DO NOT buy the brown colored rough.
NEVER buy crocked opal rough.
DO NOT buy opal rough that has dirt on it. Ask for the rough to be cleaned or ask for a discount.
When buying rough or finished opals always buy that having red as the predominant color: my opinion is that
yellow is the least desirable color for opals and single-colored gemstones.
Beware is you’re offered black finished opal. I am not aware of natural black Welo opal. The finished opal has
probably been dyed or sugar/acid-treated to give
the black background.
The Cutting of Welo Opal
The cutting of Welo opal presents nothing
unusual. The same precautions must be
observed as for cutting Australian opal or even
your jaspers or quartz-based cabachons.
There is a condition called reverse hydrophane
that makes cutting different from other gem
stones. The condition causes the vibrant colors
to disappear as the opal is cut with the addition
of water. The color(s) will eventually reappear
when the opal is dry.
FOR ALL THE MILLIONS AND MILLIONS OF
OPALS SOLD TO THE PUBLIC A QUESTION
NEEDS TO BE ASKED: WHERE ARE THEY?????
Delvers Gem & Mineral Society, Inc. - mailing address: P.O. BOX 112, Wilmington, CA. 90748
DELVINGS, c/o A. Hoekstra, editor
16643 Chicago Ave.
Bellflower, CA 90706
FIRST CLASS MAIL
Website: http://delversgemclub.wordpress.com/
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email: [email protected]
Regular Meeting of the Delvers Gem and Mineral Society
February 8th, @ 7:00 PM at the Holy Redeemer Church,
14515 Blaine Ave., Bellflower, CA
Program: Metal Detector Demonstration presented by Guynell Miller
Visitors are Always Welcome
Board Meeting (all members invited) 6:30 PM