A small, but terminated and unusually gemmy barite crystal.  

Although not particularly well known outside the US, the Linwood Mine has produced some of the country's finest (and certainly largest) barite crystals, though it had not received the same attention as Elk Creek (South Dakota), the various Colorado localities, or the Meikle Mine (Nevada).

This piece comes from a find made within the last year and a half.  Barite specimens from this mine in nearly all cases are displayable from only one side-- the back is usually heavily covered with sediment, or the point of attachment.      

Opened in 1944, the Linwood Mine is an active producer of calcium carbonate products, which are used in glass and plastic manufacture, cements and other building materials, feed, water purification, and various other chemical applications.  Given the high purity of product necessary for such uses, the presence of these barium sulfate crystals is actually considered a bad thing--when crushed into the mix, they become contaminants.

The site was originally operated as a quarry, though is now an underground mine.

So yes, this is just a piece of quartz.  The reason I am posting it however, is because it comes from the Viburnum Trend.  Just about every sample that I have ever seen from the area is either galena, calcite, or marcasite-- so I figured this was unusual enough to post.  

Also, it is worth noting that the actual mine name was recorded-- 95% of the specimens from the area (unless from a notable find) are simply labeled as "Viburnum Trend."

A specimen of purple fluorite on siderite from new production at the Yido Silver Mine.  To the untrained eye, this looks like a typical Yaogangxian specimen, but a slightly closer look reveals that the matrix is in fact siderite (rather than muscovite.)

I was offered a small group of specimens prior to Tucson which I declined due to the exorbitant prices, though I was happy to see one small lot available in Tucson as well. 

There is one bit of damage, this is best visible in the image directly below the description on the second-farthest crystal to the right.

Pieces like this are exciting because they come from a location that had previously not produced specimens. The bulk of the currently available Inner Mongolian pieces come from only 3 or 4 mine clusters ( mainly Huanggang, Rongguan and Chaobuleng)-- over 200 such mines and mine clusters have been opened over the past several years.  That pieces like this make it to the market means that there is a chance that a greater portion of those 200+ locations will eventually start to produce collectible specimens.

Although seldom seen at the large shows, interesting local calcites tend to turn up at smaller events in the Midwest, often collected by local field collectors.  This is just such a specimen, from somewhere near Manon, Indiana.

Apart from being good calcites, I like to post these as they show the diversity of a largely overlooked group of minerals (Midwestern Calcites-- if they are not from southern Illinois or Elmwood, no one cares).

A cluster of colorless calcite on matrix, from the once prolific Romanian sulfide mines. 

With Romania"s entrance the EU in 2007, the main specimen producing mines (and many others) were forced to close as they were not compatible with EU regulations.  Even for some years before that, output had been decreased,  These days the specimens are still seen for sale, just not as often as before, as the mines are sealed shut.

A nice icy green aggregate of prehnite from mali, with excellent translucency and larger than usual crystals.

A light pink, terminated Kunzite crystal from Afghanistan.  It appears to be a floater-- the bottom is etched, but I cannot find a point of attachment.

A lustrous sample of ore minerals from Colorado.  This mine operated from sometime in the 1880s until 1984, and then became a superfund site.

A sample of almandine garnet from Madagascar.

A group of calcite crystals on matrix, from the lead mining districts of Missouri.  The main double terminated crystal has no issues, the others have cleaves.

Numerous lustrous arsenopyrite crystals backing a terminated quartz crystal, from Kosovo.  The front surface of the quartz crystal is a bit rough, but it is not damage, rather calcite that has been naturally etched away leaving indentations.

A nice cluster of thin wulfenite panes in a vug from the Defiance Mine.  Little bits *will* come off during shipment.

An interesting specimen of silver sulfosalts from Uchucchacua, with a pair of small (but sharply hexagonal) pearceite crystals on the bottom front, and a quite large (but broken in half) proustite on the back. 

A colorless octahedron of fluorite from recent finds at the Huanggang mines.  There is a point of attachment on the reverse, but as you can see from the pictures, it displays well from different angles.

A cluster of quartz crystals hosting a realgar crystal that has been overgrown by a smooth layer of orpiment.

Multiple globular clusters of calcite on matrix, from the once prolific Romanian sulfide mines. 

With Romania"s entrance the EU in 2007, the main specimen producing mines (and many others) were forced to close as they were not compatible with EU regulations.  Even for some years before that, output had been decreased,  These days the specimens are still seen for sale, just not as often as before, as the mines are sealed shut.

A cluster of brownish andradite garnets from the early finds at the Huanggang Mine.

Numerous pyromorphite crystals on matrix, from one of the lesser known French pyromorphite localities.

A somewhat difficult (and older) example of British analcime.

A thumbnail specimen, featuring an orange Helvite crystal.  These specimens come from the same locality that yielded the spessartine/ smokey quartz bonanza several years ago.

The locality actually consists of a large granite hill.  At present, just about all of the workable part of that hill has been carved away to excavate for specimens.

These have not been found for a few years. 

A few deep red spessartine crystals on feldspar from the Shaigar Valley, located in the northernmost part of Pakistan.

A terminated black ilvaite crystal, attached to a bit of matrix.  The matrix is composed primarily of quartz.

Most of the time these occur off matrix.

A rare (and rather ugly) example of smithsonite from Kentucky.  It's the only one I have ever seen, and came from the collection of an individual who mainly collected material from southern Illinois, Tennessee, and the surrounded area (which includes Kentucky.)

A slab of silver bearing ore from Canada.

A terminated example of Afghan amethyst from a find made a few years back. There is some chipping near the terminaton.

A cluster of smokey quartz crystals from the Viloco mine.

Viloco is the locality better known for producing some of the world's best cassiterite specimens.

A rare thumbnail of CUBIC magnetite.  Magnetite is most commonly octahedral, and is known to occur as dodecahedrons in skarns, but cubes are somewhat harder to find.

This piece comes from an early 90's find in New York.

A reference sample of bixbyite.  This is actually quite a sizable crystal, it displays well (that is, it looks a lot more complete and cubic positioned in the perky box.)

A lustrous anatase crystal on matrix from Kharran, nicely perched on the end of its matrix. 

I didn't buy this in Tucson but found it in my basement along with a group of others from my last trip to Pakistan.  

At this price, the thing is practically a giveaway.  You would have a hard time finding one for even twice the price in Tucson.

A double terminated quartz crystal, hosting numerous other double temrinated crystals. From a find made a few years back.

A wulfenite specimen from one of the lesser known Chinese localities, the Mianning Pb/Zn mine. These Mianning wulfenites are not seen all too often, but this year one dealer had a group of particularly rich (and in some cases sizable) pieces. The wulfenite crystals are bipyramidal, the small white crystals are barite.

For all the minerals that have come from China, the country has produced a relatively small amount of wulfenite. In fact, up until the discovery of these specimens several years ago (8-9 years, I think) no good wulfenite specimens from the country were available on the market. Around 2005-2006 there was a second major wulfenite discovery near Urumqi (further north in Xinjiang A.R.) that is considerably more well known, and which produced spectacular specimens in fairly large quantities. As far as I am aware however, that second find has been worked out for some years, and apart from that occurrence and this one, I don't think there has been another Chinese locality to produce any significant wulfenites in any quantity.

A group of gemmy calcites, the larger ones showing faint marcasite phantoms, from the Linwood Mine in Iowa.  

The mine has recently received much attention for its barites, though the calcites are actually much better....

A well-exposed crystal of lazurite, on a marble matrix.  Cheap for what it is.  Please note that there are saw marks on the specimen, that is pretty common given how these things are prepared. 

The mines at Sar-e-Sang have been producing for over 6,000 years.  They supplied the lapis that adorns King Tutankhamen’s famous burial mask, as well as various Greek and Roman artifacts. Although a lot of lapidary grade lazurite now comes from Chile, crystals of this size and quality have only come from Afghanistan.

A miniature specimen, with a gray danburite crystal on a talc matrix.  The gray color comes from inclusions of magnesioriebeckite.

A reference specimen of of sampleite, hosting a couple bright blue (but very small) rosettes of the mineral on matrix.  Most of the sampleite I have seen is from Australia.

A reference sample of bixbyite.  This is actually quite a sizable crystal, it displays well (that is, it looks a lot more complete and cubic positioned in the perky box.)

This is one of only a few green fluorites that I have seen from Inner Mongolia, though it certainly has the brightest green of any I have seen from the area.

It is also extremely unusual to see green dodecahedrons from there-- the other (duller) green examples were all cubes.

 I suspect it may be from another mine in Inner Mongolia that is not Huanggang.