RockHoundBlog

Fluorescent minerals – Fluorescence

Filed under: regular postings — Gary April 18, 2010 @ 10:51 pm
Fluorescent_minerals

Fluorescent_minerals

Hannes Grobe- picture

(click “read more” below  to see what each mineral in picture is)

Gemology, mineralogy, geology, and forensics

Gemstones, minerals, fibers, and many other materials which may be encountered in forensics or with a relationship to various collectibles may have a distinctive fluorescence or may fluoresce differently under short-wave ultraviolet, long-wave ultra violet, or X-rays.

Many types of calcite and amber will fluoresce under shortwave UV. Rubies, emeralds, and the Hope Diamond exhibit red fluorescence under short-wave UV light; diamonds also emit light under X ray radiation.

Fluorescence in minerals is caused by a wide range of activators. In some cases, the concentration of the activator must be restricted to below a certain level, to prevent quenching of the fluorescent emission. Furthermore, certain impurities such as iron or copper need to be absent, to prevent quenching of possible fluorescence. Divalent manganese, in concentrations of up to several percent, is responsible for the red or orange fluorescence of calcite, the green fluorescence of willemite, the yellow fluorescence of esperite, and the orange fluorescence of wollastonite and clinohedrite. Hexavalent uranium, in the form of the uranyl cation, fluoresces at all concentrations in a yellow green, and is the cause of fluorescence of minerals such as autunite or andersonite, and, at low concentration, is the cause of the fluorescence of such materials as some samples of hyalite opal. Trivalent chromium at low concentration is the source of the red fluorescence of ruby corundum. Divalent europium is the source of the blue fluorescence, when seen in the mineral fluorite. Trivalent lanthanoids such as terbium and dysprosium are the principal activators of the creamy yellow fluorescence exhibited by the yttrofluorite variety of the mineral fluorite, and contribute to the orange fluorescence of zircon. Powellite (calcium molybdate) and scheelite (calcium tungstate) fluoresce intrinsically in yellow and blue, respectively. When present together in solid solution, energy is transferred from the higher energy tungsten to the lower energy molybdenum, such that fairly low levels of molybdenum are sufficient to cause a yellow emission for scheelite, instead of blue. Low-iron sphalerite (zinc sulfide), fluoresces and phosphoresces in a range of colors, influenced by the presence of various trace impurities.

Crude oil (petroleum) fluoresces in a range of colors, from dull brown for heavy oils and tars through to bright yellowish and bluish white for very light oils and condensates. This phenomenon is used in oil exploration drilling to identify very small amounts of oil in drill cuttings and core samples.

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Colorado Mineral & Fossil Show, Denver, CO

Filed under: Coming Events — Gary @ 10:24 pm
Dates: April 23–25, 2010
Description: Retail and wholesale dealers selling minerals, fossils, gems, jewelry, and lapidary materials. Open to the public.
Show Hours: 10 a.m.6 p.m. Friday and Saturday, 10 a.m.5 p.m. Sunday
Admission: Admission and parking are free.
Location  Holiday Inn — Denver Central, 4849 Bannock St, Denver, CO 80216-1813
Rooms: Sleeping Room Reservation Form for Show (.pdf, 32 KB)
Please provide arrival date, departure date, number of beds, smoking or non-smoking room, and how to guarantee late arrival.

California Mineral Show

Filed under: Coming Events — Gary @ 10:22 pm

Nestled in the small community of San Rafael in Marin County, our inaugural California Fine Mineral Show is sure to be a hit. Located just 45 minutes away from both Oakland Airport and San Francisco International, we have a world-class roster of mineral dealers signed up for this show.

When you’re not checking out the latest minerals, explore all that San Francisco has to offer or spend the day wine tasting in nearby Napa Valley.

Long a hot-bed of mineral collectors, we’re pleased to finally bring a Fine Mineral Show to the beautiful city of San Francisco.

So come visit us this summer and discover what’s new in the mineral world. You’ll be glad you came.

2010 Show Dates:

Friday, July 9, 2010
10A – 6P

Saturday, July 10, 2010
10A – 6P

Sunday, July 11, 2010
10A – 5P

The San Francisco Fine Mineral Show will be held at:

The Embassy Suites Hotel
101 McInnis Parkways
San Rafael, CA 94903
(415) 499-9222

California_mineral_show

California_mineral_show

Houston Fine Mineral Show

Filed under: Coming Events — Gary @ 10:16 pm
Houston_mineral_show

Houston_mineral_show

Friday, April 30, 2010
10AM – 6PM

Saturday, May 1, 2010
10A – 6PM

Sunday, May 2, 2010
10A – 5P

Welcome to the new Houston Fine Mineral Show. For 2010 we’re returning to Houston and the Houston Fine Mineral Show.

The 2009 show was absolutely unforgettable and we’re looking to do the same in 2010. Some of the finest dealers from around the world will be joining us in Houston for what we are sure will be an unforgetable show.

Located within walking distance of The Galleria, our new show will be in the heart of Houston and everything this great city has to offer.

If you have any questions or would like more information for any of our shows, please contact the Show Administrator, Dave Waisman using the information below:

Dave Waisman
(509) 458-2331
info@westwardminerals.com

AFMS/CFMS Gem Show and Convention – 2010

Filed under: Coming Events — Gary @ 10:08 pm
afms_cfms_gem_show

afms_cfms_gem_show

Show by Cheri

Show Info

When: June 18, 19, 20 2010 Time: Friday 10 a.m. – 5 p.m.
Saturday 10 a.m. – 5 p.m.
Sunday 10 a.m. – 5 p.m.
Where: So. CA University of Health Sciences Campus
16200 E. Amber Valley Drive
Whittier, California
Cost: Adult daily admission – $6
Three day admision – $15
Juniors 14 and under are free when accompanied by an adult.
Parking: Free. La Habra: Pictures Places to go in: Southern CA

Convention Info

When: June 16, 17, 18, 19, 20 2010 Scheduled Events

Hosting Club:
North Orange County
Gem & Mineral Society

Websites:
AFMS www.amfed.org
Click here for Registration forms