RockHoundBlog

Mexico’s Cueva de los Cristales (Cave of Crystals)-largest natural crystals ever found!

Filed under: Great Finds-specimens,regular postings — Gary May 25, 2007 @ 9:05 am

Giant Crystal Cave’s Mystery Solved

Stefan Lovgren
for National Geographic News
April 6, 2007

It’s “the Sistine Chapel of crystals,” says Juan Manuel García- Ruiz.

cave_of_crystals Mexico’s Cave of Crystals contains some of the world’s largest known natural crystals—translucent beams of gypsum as long as 36 feet (11 meters). A new study says the gems reached their vast sizes thanks to a peculiar combination of consistent volcanic heat and a rich watery mixture.

The geologist announced this week that he and a team of researchers have unlocked the mystery of just how the minerals in Mexico‘s Cueva de los Cristales (Cave of Crystals) achieved their monumental forms.

Buried a thousand feet (300 meters) below Naica mountain in the Chihuahuan Desert, the cave was discovered by two miners excavating a new tunnel for the Industrias Peñoles company in 2000.

The cave contains some of the largest natural crystals ever found: translucent gypsum beams measuring up to 36 feet (11 meters) long and weighing up to 55 tons.

“It’s a natural marvel,” said García-Ruiz, of the University of Granada in Spain.

To learn how the crystals grew to such gigantic sizes, García-Ruiz studied tiny pockets of fluid trapped inside.

The crystals, he said, thrived because they were submerged in mineral-rich water with a very narrow, stable temperature range—around 136 degrees Fahrenheit (58 degrees Celsius).

At this temperature the mineral anhydrite, which was abundant in the water, dissolved into gypsum, a soft mineral that can take the form of the crystals in the Naica cave.

The new findings appeared in the April issue of the journal Geology.

WAUSEON, OHIO-FULTON COUNTY FAIRGROUNDS-JEWELRY, ROCK, GEM, & MINERAL SHOW

Filed under: Coming Events,regular postings — Gary @ 8:57 am

WAUSEON, OHIO

FULTON COUNTY FAIRGROUNDS JUNIOR FAIR BUILDING
ON RT. 108 North of OHIO TURNPIKE Exit 34
June 1, 2, 3, 2007 Friday 12 p.m. – 7 p.m. Saturday 10 a.m. – 7 p.m. Sunday
11 a.m. – 4 p.m.

JEWELRY, ROCK, GEM, & MINERAL SHOW
“ROCKS! WE DIG EM’ ”
JEWELRY, FOSSILS, MINERALS, LAPIDARY SUPPLIES & MORE
FREE ADMISSION
Fun for the whole family!
Fossil dig and new this year BEAD RALLY
For more info eprzyb@tc3net. com (will send .PDF of flyer with map)

PGMC-CFMs 2007 Show w/scientist Richard Wade- Palmdale Gem & Mineral

Filed under: Coming Events,regular postings — Gary May 21, 2007 @ 9:51 pm

June 15, 16, 17, 2007 PGMC-CFMs 2007 Show at the Fairgrounds in
Lancaster off Frwy 14 at Avenue H. Field Trip each day. Vendors,
exhibits,seminars, Rusty Relics, more!

We just signed Richard Wade for 3 seminars on Sunday, June 17 at the
show. Through an interactive presentation, scientist Richard Wade will
explain how the dinosaurs lived and died. Artifacts and replicas of
fossils and bones on display.

Come celebrate 50 Years of Rock’N Gems, Palmdale Gem & Mineral is 50
years old, WOW! Older than dirt – not quite.

More info: www.palmdalegems. org

FORT WORTH, TEXAS: 56th annual show, “Let’s Rock”; Fort Worth Gem & Mineral Club

Filed under: Coming Events,regular postings — Gary @ 9:46 pm

May 26-27–FORT WORTH, TEXAS: 56th annual show, “Let’s Rock”; Fort
Worth
Gem & Mineral Club; Amon Carter Exhibits Bldg., Will Rogers
Memorial Center, 3401 W. Lancaster; Sat. 9-5, Sun. 10-5; adults $4,
seniors $3, children under 12 free; more than 25 dealers, exhibits,
kids’ games, hourly door prizes, grand prize drawing, silent auction;
contact Steve Hilliard, P.O. Box 418, Decatur, TX 76234, (817)
925-5760, or Kay Anderson, (817) 597-8912; e-mail:
wkanderson@sbcgloba l.net.

Mineral/rock of the day- Serpentine -California’s state rock

Filed under: Mineral of the day,regular postings — Gary May 20, 2007 @ 9:42 pm

SerpentineSerpentine_2Overview

Serpentine is said to owe its name either to its serpent-like colours and patterns or from an old belief that the stones were effective protection from snake bites. They have their origins in metamorphic alterations of peridotite and pyroxene. Serpentines may also pseudomorphously replace other magnesium silicates. Alterations may be incomplete, causing physical properties of serpentines to vary widely. Where they form a significant part of the land surface, the soil is unusually high in clay.

Antigorite is the polymorph of serpentine that most commonly forms during metamorphism of wet ultramafic rocks and is stable at the highest temperatures — to over 600°C at depths of 60 km or so. In contrast, lizardite and chrysotile typically form near the Earth’s surface and break down at relatively low temperatures, probably well below 400°C. It has been suggested that chrysotile is never stable relative to either of the other two serpentine polymorphs.

Samples of the oceanic crust and uppermost mantle from ocean basins document that ultramafic rocks there commonly contain abundant serpentine. Antigorite contains water in its structure, about 13 percent by weight. Hence, antigorite may play an important role in the transport of water into the earth in subduction zones and in the subsequent release of water to create magmas in island arcs, and some of the water may be carried to yet greater depths.

(more…)

The Minnesota Mineral Club- Check out the club! Great lakes/great rocks 2007 show

Filed under: Club Rollcall (hello's),regular postings — Gary May 11, 2007 @ 11:16 pm

Minnesota’s state gemstone

MMC members successfully lobbied the state legislature to have the Lake Superior Agate named as the state gemstone.  This is just one aspect of the club’s affair with Lakers.  In 1988, the club hosted the “Night of the Lake Superior Agate” where members and guests could actually see some of the more famous Lakers and hear from agate author, club member Scott Wolters.  In 1995, Night of the Agates II again brought many local agate lovers together for an all agate exhibit and presentation.  Night of the Agate III is tentatively planned for 2007 or 2008, as a prelude to “A World of Agates” scheduled for 2012.

Club member Mike Carlson created the coffee table book “Beautiful Agates” with photos by fellow club members Pete Rodewald and Dennis Westman and lapidary work by several club members. Pete and Mike, along with member Larry Costigan and his son Brian were invited to participate in the international Agate Show held in Munich Germany in October 2005.

A club hello to the Minnesota Mineral Club, check out their site :)
ALso Oct 20/21st they are having a Great Lakes/ Great Rocks show, click on the link for full rock show info- http://www.minnesotamineralclub.org/MMC2007show.pdf

Unconventional Lapidarist-Northwest Arkansas Gem, Mineral, and Jewelry Show

Filed under: Coming Events,regular postings — Gary May 4, 2007 @ 10:44 pm

Unconventional Lapidarist would like to invite you to the…..

Northwest Arkansas Gem, Mineral, and Jewelry Show
May 5 & 6, 2007
Vineyard Room of the Grapevine Treasures Mall
Rogers, Arkansas
Saturday 10:00am to 6:00pm
Sunday 11:00am to 5:00pm

There will be designer cabochons, jewelry, lapidary rough, equipment and
tools, collector’s carvings, spheres, and eggs, mineral specimens, and
so much more.