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The Mineral Review
How the review works
The aim of the review is to establish material that is of scientific merit and specimens which are good representatives, possessing public potential for display and community events. These two criteria do not necessarily go hand in hand; as a specimen may have a fantastic scientific research potential, but may not be visually impressive. Therefore the specimens are graded against two separate criteria: Scientific Merit (as a numerical value of stars) and Public Engagement (as a Gold, Silver or Bronze status).
For a more in depth look into the review criteria, click on the “Review Criteria” tab in the tool bar above.
The Mineral Review
The mineral collection consists of 181 trays containing 4,492 specimens from around the world. The bulk of the collection was collected between the 1890’s and 1930’s from mines and locations that are now closed or have protective legislation and considered to be of significant historic importance. This includes numerous UK specimens from: Herodsfoot Mine and Virtuous Lady Mine in Cornwall, Susannah Mine in Lanarkshire, Ecton Copper Mine in Staffordshire, Blackdene Mine in County Durham, and the West Cumbrian Ore Field in Cumbria.
This wealth of material means Leeds Museum houses an impressive collection of specimens from local region, broader UK material, with European and other world-wide minerals.
Monica reviewing in store.
The huge amount of material created a dilemma as to which method would suit the review. It was decided to be conducted in two methodologies.
One method was a rapid, systematic, tray by tray investigation, often in the store, with trays containing a variety of minerals.
Overview of the Fluorites
The second method was to lay out the trays of an entire sub-category of a particular mineral type to get a broad overview; then focus on the more striking specimens. This method worked very well for the larger collections of Fluorites and Quartz.
Dr Monica Price led the review over three days, which resulted in the discovery of some incredible and important specimens.
Rather than give a day-by-day account as in previous reviews; the results of this review will occur as an overview with some of the many highlights, in a descending order of “wow” factor and awards.
The “WOW” specimens.
Previous reviews have sometimes had the occasional “wow” when examining specimens, but the minerals seemed to have more than normal. 10 specimens received a sharp intake of breath, then followed by a “wow” from Monica. This could be interpreted as a new Platinum category, but they will be just highlighted as the “wow” specimens. Below are eight of the nine Gold specimens, and one Silver specimen that received this accolade.
Specimens scoring 3 Gold stars with the wow factor:
Leedm.B.1952.56.0505
A wonderful and important specimen of Lanarkite (3 Gold stars – Leedm.B.1952.56.0505) from the Susannah Mine in Lanarkshire, Scotland.
Leedm.B.1952.56.0178
The rare and incredible lead mineral, Matlockite (3 Gold stars – Leedm.B.1952.56.0178) from Derbyshire, England.
Specimen scoring 2 Gold stars with the wow factor:
Leedm.B.1952.56.0153
An amazing specimen of the important titanium ore mineral, Rutile (2 Gold stars – Leedm.B.1952.56.0153) from Zinnwald, Czech Republic. Exhibiting genicular twinning or knee twin, as a change in the crystal shape that resembles a knee joint.
Specimens scoring 1 Gold star with the “wow” factor:
Leedm.B.1990.01.0212
A wonderful example of a Nail-head Calcite crystal (1 Gold star – Leedm.B.1990.01.0212) from the Ecton Copper Mine in Staffordshire, England.
Leedm.B.1952.56.0159
An incredible specimen of the important tin ore mineral Cassiterite (1 Gold star – Leedm.B.1952.56.0159) from Zinnwald, Czech Republic.
Leedm.B.1952.56.0405
A wonderful specimen of the Zeolite variety Chabazite (1 Gold star – Leedm.B.1952.56.0405) from Ústí nad Labem, Czech Republic; formed as a result of the metamorphism of trapped bubbles in lava.
Leedm.B.1990.01.0161
A beautiful specimen of Fluorite (1 Gold star – Leedm.B.1990.01.0161) in fantastic condition from County Durham, England.
Leedm.B.1979.02.0600
A spectacular specimen formed by the weathering of copper minerals as Azurite (1 Gold star – Leedm.B.1979.02.0600) from the région parisienne, France; currently on display in the Museum.
Specimen scoring 1 Silver with the wow factor:
Leedm.B.1952.56.0021
The scarce and remarkable copper ore specimen Chalcocite (1 Silver star – Leedm.B.1952.56.0021) from Cornwall, England.
The Gold specimens.
Leedm.B.1952.56.0231
A wonderful specimen of Calcite (2 Gold stars – Leedm.B.1952.56.0231) from the historically important Herodsfoot Mine in Cornwall, England.
Leedm.B.1982.01.06
A truly beautiful copper and aluminium phosphate specimen of Turquoise (2 Gold stars – Leedm.B.1982.01.06) from Cornwall, England.
Leedm.B.1952.56.0315
A specimen of the rare mineral Phosgenite (2 Gold stars – Leedm.B.1952.56.0315) from Derbyshire, England.
Leedm.B.1952.56.0292
A stunning and important example of the copper variety of Smithsonite (2 Gold stars – Leedm.B.1952.56.0292) from Cumberland, England.
Leedm.B.1982.01.03
A truly beautiful and often unseen specimen of an uncut Ruby within its matrix (2 Gold stars – Leedm.B.1982.01.03) from Mysore, India.
Leedm.B.1990.01.0170
A very striking specimen of Fluorite (1 Gold star – Leedm.B.1990.01.0170) from the Blackdene Mine in County Durham, England.
Leedm.B.1979.02.0494
A wonderful and interesting iron ore specimen of Hematite with Smoky Quartz (1 Gold star – Leedm.B.1979.02.0494) from the West Cumbrian Ore Field, Cumbria, England.
Leedm.B.1952.56.0418
A stunning specimen of Epidote (1 Gold star – Leedm.B.1952.56.0418) from the Tyrol, Austria; currently on display in the Museum.
Leedm.B.1979.02.0362
A wonderfully prepared and organic looking Quartz Chalcedony (0 Gold stars – Leedm.B.1979.02.0362) from an unknown location.
Leedm.B.1937.13.28B
A spectacular and fibrous Natrolite (0 Gold stars – Leedm.B.1937.13.28B) from an unknown location.
The Silver specimens.
Leedm.B.1952.56.0161
An incredible naturally magnetic and iron ore specimen Magnetite (2 Silver stars – Leedm.B.1952.56.0161) from an important site in Thuringia, Germany.
Leedm.B.1937.13.07.01
A breath taking specimen of Native Silver (2 Silver stars – Leedm.B.1937.13.07.1) from Kongsberg, Norway.
Leedm.B.1952.56.0312
A very good example of Phosgenite (2 Silver stars – Leedm.B.1952.56.0312) from Derbyshire, England.
Leedm.B.1952.56.0303
An important specimen of Rhodochrosite (2 Silver stars – Leedm.B.1952.56.0303) from Cornwall, England; formed in hydrothermal veins.
Leedm.B.1952.56.0202
An uncommon specimen of Malachite featuring large crystal formation (2 Silver stars – Leedm.B.1952.56.0202) from Siegen-Wittgenstein district, Germany.
Leedm.B.1952.56.0180
A beautiful specimen of Fluorite (2 Silver stars – Leedm.B.1952.56.0180) from Cornwall, England; currently on display in the Museum.
Leedm.B.1952.56.0106
A wonderful specimen of Smoky Quartz (1 Silver star – Leedm.B.1952.56.0106) from the Reichenbachtal valley in Oberhasli, Switzerland.
Leedm.B.1952.56.0450
An interesting specimen of botryoidal “starburst” clusters of Wavellite (1 Silver star – Leedm.B.1952.56.0450) from Clonmel, Ireland; formed in hydrothermal veins.
Leedm.B.1998.03.0593
A wonderful antimony ore specimen of Bournonite (1 Silver star – Leedm.B.1998.03.0593) from the historically important Herodsfoot Mine in Cornwall, England; exhibiting the classic cog-wheel twinned crystals.
Leedm.B.1998.04.069.1
A very good specimen of Clinochlore (1 Silver star – Leedm.B.1998.04.069.1) from Piedmont, Italy; currently on display in the Museum.
Leedm.B.1938.02.307
A rare and beautiful specimen of an uncut Emerald in a Schist matrix (1 Silver star – Leedm.B.1938.02.307) from an unknown location.
Leedm.B.1938.02.311
A striking cluster of the silicate gem specimens Tourmaline (0 Silver stars – Leedm.B.1938.02.311) from an unknown location.
Leedm.B.1979.02.0599
A wonderful specimen of Azurite (0 Silver stars – Leedm.B.1979.02.0599) from an unknown location.
The Bronze specimens.
Leedm.B.1990.01.0113
A good example specimen of Fluorite (2 Bronze stars – Leedm.B.1990.01.0113), rare for its location in Cornwall, England; exhibiting unusual etched patterns on the bevelled edge of the crystal.
Leedm.B.1952.56.0308
A wonderful and rare specimen of Siderite crystals (2 Bronze stars – Leedm.B.1952.56.0308) from the historically important, Virtuous Lady Mine in Cornwall, England.
Leedm.B.1952.56.0346
An uncommon and often rare in collections, specimen of Stolzite (2 Bronze stars – Leedm.B.1952.56.0346) from Cornwall, England.
Leedm.B.1952.56.0069
A very nice example of the rare mineral Stephanite (2 Bronze stars – Leedm.B.1952.56.0069) from the Mittelsachsen district, Germany.
Leedm.B.1982.02.02
A beautiful and uncut corundum gem of Sapphire (1 Bronze star – Leedm.B.1982.02.02) from an unknown location.
Leedm.B.1979.02.0926
A beautiful specimen of the blue Beryl Aquamarine (1 Bronze star – Leedm.B.1979.02.0926) from Russia.
The review covered 4,492 specimens, establishing the following summary; with an unprecedented amount of material reviewed and scored. The Clear specimen have not been mentioned or photographed, but contained some interesting mineral specimens, which may not have an immediate appeal, but are of research value.
Gold = A truly amazing specimen; Silver = A very good specimen that has great potential; Bronze = A good specimen which can demonstrate a particular feature; Clear = A specimen that has limited visual qualities.
3 stars = High scientific importance; 2 stars = Moderate scientific importance; 1 star = Fair scientific importance; 0 stars = Supported by limited or no documentation.
Monica’s summary of the mineral collection.
It was very pleasing to find an interesting, quality collection of minerals in Leeds Museum. Most were field collected before or during the last century; very little dates from the end of the 20th or the current century. The evaluation did not allow time for any details of collectors to be checked, but there were some dealers’ labels among the original labels stored with specimens. Older labels include those of the German company F. Krantz of Bonn. More recent ones include Gregory, Bottley and Lloyd, and Isis Minerals, both reputable companies.
Strengths
The collection comprises overwhelmingly the more common species, many in a good range of varieties. Of the relatively small number of rarer species found in the collection, there were some very fine examples, for example the lead minerals matlockite, phosgenite,and leadhillite.
The collection is particularly strong in specimens from Derbyshire, Yorkshire, the lead mines of the Weardale area of Co. Durham, and the west Cumbrian iron ore-field, but overall it has large numbers of specimens from a wide variety of UK localities, including the Lake District, Flintshire, Leadhills and Wanlockhead in Scotland, the West Country and the Isle of Man. These are the classic UK localities up to the Second World War and as nearly all the mines and quarries are now closed, the specimens are all the more important as both historical and scientific resources.
I would particularly note the substantial number of specimens for which not only is the mine name specified, but also the level or vein in the mine. These offer particular interest and potential for those carrying out topographic mineralogy research such as the more scientific members of the Russell Society.
As might be expected in a collection (or series of collections) of this time largely accumulated through collectors’ purchase and exchange rather than primary fieldwork, there are also good locality specimens from overseas, predominantly Germany, Russia and eastern European countries. These widen the diversity of species available for display and study. They rarely have such detailed locality information – it seems there was little demand on dealers to provide this information, and indeed some dealers were reluctant to reveal their sources.
Weaknesses
The Leeds Collection particularly lacks good pyrite (crystals from Peru or from Navajun, Spain are more stable than most UK material), sapphire (a gem variety of corundum, blue or other colours), and rhodochrosite (manganese carbonate – pink crystals found in weathered manganese ore deposits), and has little in the way of rare earth element minerals.
Locality information is key to mineral specimens and their potential for general interest and particularly for research. There were some specimens with no locality data at all, particularly varieties of quartz, but the proportion was not excessive. It would be possible for some experienced collectors and mineral curators to attribute data for at least some of these time constraints did not allow me to focus on doing this.
To Close
Leeds Museum has a good mineral collection, which has lots of potential for use at various levels. In my experience, the collection is not well known and I think a formal article in the Russell Society Journal or an informal one for the Society’s newsletter would bring the collection to the attention of amateur and professional researchers.
Please visit Monica Price’s blog for her experience.
The minerals, along with all the other collections are open and free for anyone to view by appointment, just call Leeds Discovery Centre on 0113 378 2100 or email discovery.centre@leeds.gov.uk
I would like to take this opportunity to thank Monica for going that extra mile in this review. The amount of material covered was incredible and tackled with such determination and desire to discover the treasures within the collection. “Thank you” for a wonderful review, and three amazing days.
The Petrology Review
How the review works
The aim of the review is to establish material that is of scientific merit and specimens, which are good representatives, possessing public potential for display and community events. These two criteria do not necessarily go hand in hand; as a specimen may have a fantastic scientific research potential, but may not be visually impressive. Therefore the specimens are graded against two separate criteria: Scientific Merit (as a numerical value of stars) and Public Engagement (as a Gold, Silver or Bronze status).
For a more in depth look into the review criteria, click on the “Review Criteria” tab in the tool bar above.
The Petrology review
Petrology is sub-divided into three main groups: Igneous, Metamorphic and Sedimentary.
The Sedimentary petrology collection is the largest of the three groups, and consists of 74 trays containing 1,132 specimens. The amount of material created a huge dilemma as to which method would suit the review. It was decided to be conducted as a rapid, systematic, tray by tray investigation, rather than an initial overview of the entire collection; followed by an in depth look at a compiled shortlist.
A summary of reviewed material
Limestones & Dolomites, Chalks, Sandstones, Siltstones, Mudstones, Shales, Conglomerates, Hydrocarbons & Organics*, Extraterrestrial rocks, and Features**.
Sian with a few trays.
* “Organics” refers to material of an organic nature, this differs to palaeobotany, and features: Amber, Copalite, Jet, Bitumen, Coal and Elaterite.
** “Features” refers to sedimentary rocks which exhibit unusual structures: wave or ripple preservation, Cone-in-cone and Septarian nodules.
Day One.
Dr Sian Davies-Vollum led the review with some wonderful and curious specimens being discovered and highlighted some historically important UK material.
Leedm.B.1998.03.0608
Notably the striking landscape marble or Cotham marble (1 Gold star – Leedm.B.1998.03.0608) from Bristol, a highly calcareous stromatolitic limestone and is prized for it’s “landscape” or hedgerow patterns.
Leedm.B.1993.03.0029
Also, Shale with beef (2 Silver stars – Leedm.B.1993.030029) from Charmouth in Dorset, a very distinct shale with a fibrous calcite structure, noted as a Lower Jurassic marker bed.
Leedm.B.TN2965
Plus the figured specimen of Rhaetic bone bed (2 Silver stars – Leedm.B.TN2965) from Aust Cliff in Gloucestershire, which exhibits no fossil material but contains numerous fine tapering lenses.
In addition, three wonderful and unusual specimens of Magnesian limestone concretions (1 Silver star – Leedm.B.1980.06.0096.1-3) found near Durham.
Leedm.B.1980.06.0096.1-3
The final tray of limestones.
The first day of the review managed to cover limestones, dolomites, chalks, shales and mudstones; featuring some striking banded mudstones (not pictured). A lot of material was reviewed, with limited highlights.
Day Two.
The second day of the review commenced with sandstones, and managed to cover conglomerates, siltstones, features, organics and extraterrestrial rocks. These yielded a far greater number of notable specimens, with some surprising discoveries.
Flexible sandstone
One of the highlights was a number of very strange and amazing Itacolumite or Flexible sandstone specimens from India. Click here to witness the flexibility. Also some uncommon but wonderful specimens of Imatra stones (2 Bronze stars – Leedm.B.TN411) from Scotland, odd little concretions often referred to as “Fairy Stones”.
Leedm.B.TN411
Leedm.B.2011.34
The ultimate highlight for Sian was a very unusual and rare specimen of Desiccation cracks (2 Gold stars – Leedm.B.2011.34), as a discontinuous band of pink mud flakes with an unusual lower surface of rip-up clasts.
Leedm.B.2009.076
Another wonderful specimen is a small and often easily overlooked sample of Fulgurite (1 Gold star -Leedm.B.2009.076). A small tube of fuse quartz formed as the result of a lightning striking.
There was also an interesting Jurassic Laminated sandstone (1 Silver star – Leedm.B.2010.50) from Cayton bay in Yorkshire, featuring vertical burrow structures and carbonaceous root deposits with mica flecks.
Leedm.B.2010.50
The collection contains numerous Septarian nodules, these are very common, but two noteworthy specimens are (0 Bronze stars – Leedm.B.TN5412); an interesting complete nodule with crack infill in relief, as a result of weathering. The other is (0 Bronze stars – Leedm.B.2011.33), a split nodule in cross section, illustrating the extensity of cracking throughout the calcite cemented nodule.
Leedm.B.TN5412
Leedm.B.2011.33
Leedm.B.TN1803
Leedm.B.1980.06.0062.1-2
Another highlight was a very unusual specimen of Conglomerate (0 Silver stars – Leedm.B.TN1803), featuring numerous small rounded clasts coated in a green film.
Along with another wonderfully named conglomerate; Pudding stone (0 Bronze stars – Leedm.B.1980.06.0062.1-2), consisting of rounded agate clasts in a very fine grained matrix. The specimen has been cut and polished to emphasise its structure.
The Hydrocarbons and organics revealed some striking specimens of Jet and Bituminous Coal with amazing lustres, plus some stunning samples of resin Copalites with organic inclusions.
Leedm.B.1955.61.0229
A particular highlight is this specimen of Amber (1 Silver star – Leedm.B.1955.61.0229) from the Baltic Coast, with some obscured but strange unidentified inclusions.
Leedm.B.TN5396
The collection also contains a number of somewhat peculiar specimens know as Cone-in-cone (1 Silver star – Leedm.B.TN5396), these are sedimentary features as a series of concentric cones nested inside each other.
Lastly, the extraterrestrial material comprises of four Pallasite Meteorites from various locations around the world. Two of the specimens are whole and two occur as cut cross-sections, revealing the striking interior of iron with olivine infill voids (3 Gold stars – Leedm.B.1985.05.01) from the Haviland Crater in Kansas, USA.
Leedm.B.1985.05.01
Looking at the larger specimens.
The review covered 1,132 specimens, establishing the following summary.
Gold = A truly amazing specimen; Silver = A very good specimen that has great potential; Bronze = A good specimen which can demonstrate a particular feature; Clear = A specimen that has limited visual qualities.
3 stars = High scientific importance; 2 stars = Moderate scientific importance; 1 star = Fair scientific importance; 0 stars = Supported by limited or no documentation.
Summary of the Sedimentary petrology collection.
Strengths
1) There are good suites of sedimentary rocks collected from the region. This is particularly true for rocks originating from the Carboniferous Coal Measures. They could be used to ‘tell a story’ about the rock sequences in which coal is found and the significance of these in the region.
2) There is a good breadth of sedimentary rock types in the collection with most key rock types included. This range of rocks can be used as a basis for teaching sedimentary petrology and interpretations of sedimentary rocks.
3) There are a number of unusual sedimentary rocks represented by multiple hand specimens e.g. Itacolumite (flexible sandstone from India) and ‘landscape marble’ (Cotham marble, a stromatolitic limestone).
Weaknesses
1) There are many unusual and/or interesting samples that lack information about where they were collected. This lack of information makes it difficult for any researcher to place these samples into stratigraphical or geographical context.
2) Some of the samples are in need of cleaning and preparing to reveal details of their petrology.
3) Apart from a collection made from central Europe, most specimens come from the UK.
I would like to say a heartfelt “thank you” to Sian for reviewing this volume of material, and bringing to light such an interesting and often overlooked series of rocks over the two intense, but fun days.
The sedimentary petrology, along with all the other collections are open and free for anyone to view by appointment, just call Leeds Discovery Centre on 0113 378 2100 or email discovery.centre@leeds.gov.uk
The Rock Type Collection
The rock type or petrology collection consists of 190 trays of 4,500 specimens featuring Igneous, Metamorphic and Sedimentary rocks from the UK, around the world and beyond….
A large slab of Wenlock limestone.
The bulk of the collection is sedimentary, represented by numerous sandstone, limestone and mudstone specimens, also containing some stunning examples of siltstone, dolostone, marl and chalk.
We also have a strong representation of igneous petrology predominantly consisting of basalt, gabbro, diortie and granite specimens; with additional examples of peridoite, picrite, syenite and trachyte, and stunning specimens of pegmatite.
There are also some wonderful examples of andesite and rhyloite with amazing obsidian glass, pitchstone and snowflake obsidian specimens. Not to mention volcanic pumice and beautiful banded tuff.
A great example of a metamorphic schist.
The metamorphic petrology features some wonderful slate, schist, amphibolite and gniess specimens; with some truly spectacular phllite, quartzite and marble.
A wonderful specimen of puckered slate.
The collection also contains some weird and wonderful geological features, notably the incredible cone-in-cone formation, septarian nodules and preserved ripple beds.
A specimen of cone-in-cone geological feature.
Some of the material really is “out of this world” with a few examples of meteorites and the products of a meteor impact tektites. The strangest of all, is a small unassuming specimen of fused sand, the preserved moment in time of a lightning strike.
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