Minerals from the Linwood Mine, Scott County, Iowa

The Linwood Mine is located right along the Mississippi River between Davenport and Buffalo just west of I-280 in Scott County, located in the extreme east central part of Iowa.  The Linwood Mine is currently mining solely for limestone.  Throughout the course of mining, open pockets lined with a variety of minerals are encountered, including calcite, marcasite, sphalerite, barite, pyrite, and quartz.  While the mineralization is pretty consistent from pocket to pocket (Linwood material is fairly recognizable), pockets do tend to have their own distinctive crystallization and/or mineral combinations so new finds add a little variety and anticipation to a suite of minerals from this location and Midwest USA collections.

NOTE:  We are not the owners of the Linwood Mine - please do not call us for employment opportunities or requests to collect in the mine.  Thank you for your understanding!  Any questions related to the mine should be directed to the mine itself.

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Linwood 26:  Calcite, Marcasite on limestone:  9 x 8 x 5 cm (3.5 x 3.2 x 2 inches) - $20.00

 

 

 

 

 

Calcite, Marcasite on limestone:  Blocky calcite crystals with marcasites in association both near and in the calcite.  There is some contacting and cleaving to the base and on three sides of the calcite but when displayed as shown in the top photograph this damage is quite minimal.  Largest calcite crystal is nearly 5 cm (2 inches) on edge.  $20.00

 

 

Linwood 27:  Calcite:  4 x 3 x 3.6 cm (1.6 x 1.2 x 1.5 inches) - $10.00

 

Linwood 04:  Calcite on matrix:  11 x 9 x 3 cm (4.3 x 3.5 x 1.2 inches) - $15.00

Calcite:  Fine miniature specimen featuring calcite crystals coating a limestone matrix.  The largest calcite at the top is un-damaged and measures approximately 1.8 cm across.  The only damage on the specimen is very slight contacting to the back and base.  Specimen is mounted on a plastic base.  $10.00

 

 

Calcite on matrix:  A two-sided specimen featuring a drusy coated limestone front with a single 2 cm (0.8 inch) calcite crystal positioned in a small crevice in the limestone.  The calcite is undamaged.  The back side has several smaller calcite crystals on the limestone base.  Some contacting is found along one edge.  A good reference specimen for the locality.  $15.00

 

Linwood 28:  Calcite on limestone:  15 x 8.5 x 7.5 cm (5.9 x 3.35 x 2 inches) - $50.00

 

Linwood 06:  Calcite on matrix:  13 x 12 x 4 cm (5.1 x 4.7 x 1.6 inches) - $50.00

Calcite on limestone:  Cabinet sized specimen featuring calcite crystals coating a limestone matrix base.  The calcites range in size from a few millimeters up to about 1.5 cm on edge.  Some slight cleaves or rubs are found in a few places on the specimen but they are mainly confined to the edges.  Minor marcasite in association.  $50.00

 

 

Calcite on matrix:  Cabinet sized specimen featuring a limestone matrix entirely covered with calcite crystals.  The calcites range in size from just a few millimeters up to one crystal that is 3 cm (1.2 inches) on edge.  An area of contact is found on the lower left portion of this specimen.  This could be carefully trimmed to improve the specimen.  Otherwise, just a few trivial small rubs or nicks on the remainder of the specimen.

 

Linwood 07:  Calcite with Calcite/Marcasite inclusions:  12 x 9.5 x 2.5 cm (4.7 x 3.7 x 1 inches) $20.00

 

Linwood 18:  Calcite:  4 x 3.5 x 2 cm (1.6 x 1.4 x 0.8 inches) - $12.00

 

Calcite with Calcite/Marcasite inclusions:  A highly dissolved (but stable) limestone matrix base is nearly coated entirely on the top with small calcite crystals and a small pocket of larger crystals toward the back of the specimen.  The calcite crystals in the back are up to 3.2 cm (1.3 inches) across.  The largest crystal at the left has some inclusions of likely marcasite.  Some contacting is present to the upper right edge of the specimen, otherwise clean.

 

 

 

 Calcite:  Scalenohedral calcite crystals are positioned on a limestone shard.  One of the larger calcite crystals is slightly tipped but other than typical slight edge contact, no other damage.  Nice miniature from this mine.

 

 

 

Linwood 09:  Calcite on matrix:  8 x 6 x 5 cm (3.2 x 2.4 x 2 inches) - $40.00

 

Linwood 17:  Calcite:  4.5 x 3.5 x 1.2 cm (1.8 x 1.4 x 0.5 inches) - $12.00

 

Calcite on matrix:  A single large (for the locality) 6 cm (2.4 inch) calcite crystal with many smaller calcites is perched on a limestone matrix.  There are many options to display this specimen, however the bottom left photo may be the best given the crystal structure present and the fact that there is a ding on the upper left corner of the crystal.  Normally I do not buy anything that has a ding on it, but given the large crystal size and multiple display options, I went ahead and purchased this one.  Individual crystals of this size are not available in great numbers from the mine.

 

 

 

 

Calcite:  Very nice small miniature sized specimen featuring three dominant calcite crystals.  Just a little bit of matrix on the base.  Damage wise there is a teeny tiny rub on the left edge of the furthest left crystal - this could probably be remedied with mineral oil.  Extremely minor contact on the back of one calcite crystal where it joins the matrix.  All in all fine miniature.

 

 

 

 

Linwood 12:  Calcite, Pyrite, Marcasite:  14 x 9 x 10 cm (5.5 x 3.5 x 3.9 inches)- $60.00

 

 

 

 

 

 

 

 

 

 

Calcite, Pyrite, Marcasite:  Very nice cabinet sized specimen that has a good coverage of calcite crystallization nearly all around the specimen except on the back.  Somewhat cloudy or opaque calcite crystals up to 3 cm (1.2 inches) cover the limestone base along with pockets of pyrite both on the matrix and on/in some calcite crystals.  Minor marcasite in association.  Contacting along the edge and rubs to a calcite on the back are the only areas of damage.  Quality large hand sized specimen from this mine.

 

Linwood 13:  Calcite, Marcasite:  12 x 11 x 5 cm (4.7 x 4.3 x 2 inches) - $50.00

 

 

 

Calcite, Marcasite:  Neat "mound-like" specimen featuring a dense covering of small (less than a centimeter) calcites with scattered marcasite clusters that wrap around to the back side of the piece.  Specimen is somewhat unique in my experience in terms of the shape and crystal coverage, and the marcasites add a nice touch.  Contacting is present and confined to the back of the specimen.  It does need a little assistance to sit up for display.  The photos do not totally convey the piece entirely.

 

 

 

 

 

 

 

Linwood 15:  Calcite, Marcasite on matrix:  8.5 x 8 x 3 cm (3.35 x 3.2 x 1.2 inches) - $30.00

 

Linwood 23:  Calcite:  3.2 x 2.5 cm, 5 cm tall (1.3 x 1 inches, 2 inches tall) - $12.00

 

Calcite, Marcasite on matrix:  Small cabinet specimen featuring a limestone base entirely covered with scalenohedral calcites of varying sizes.  The larger crystals are near the edge of the specimen and are up to 2.5 cm (1 inch) in length.  Marcasite is in association with the specimen.  One calcite along the edge of the specimen is cleaved but does not really detract from the overall appearance.

 

 

Single partial stacked calcite crystal with minor marcasite on the back.  Crystal is cleaved on the base allowing for display as shown in left photograph.  Very, very slight rub on left back quadrant of the upper termination.

 

 

Linwood 30:  Marcasite on limestone:  7 x 5.5 x 2 cm (2.8 x 2.2 x 0.8 inches) - $30.00

 

Linwood 31:  Marcasite, Calcite on limestone:  6.5 x 5.5 x 2.5 cm (2.6 x 2.2 x 1 inches) - $25.00

A thin limestone matrix plate is nearly coated with marcasite crystals.  Some iridescent coloring is present especially on the left side of the specimen.  $30.00

 

 

Bladed marcasite crystals are perched upon a limestone matrix base.  There is also a single small calcite in the middle of the marcasite grouping (see lower right close-up photograph).  Slight contacting is present on one edge and a small protrusion could be trimmed off very carefully to make a more balanced specimen.  $25.00

 

Linwood 32:  Sphalerite with Chalcopyrite:  3.6 x 3.5 x 3 cm (1.45 x 1.4 x 1.2 inches) - $15.00

 

Linwood 33:  Marcasite with Calcite:  16 x 10 x 5.5 cm (6.3 x 3.9 x 2.2 inches) - $75.00

Sphalerite with Chalcopyrite:  Blocky somewhat crude sphalerite crystal with chalcopyrite and/or marcasite serving as the iridescent coloring on some crystal faces.  There is some contacting and the crystal faces are not as well-defined as one would perhaps like, but somewhat of an unusual specimen from this mine.  $15.00

 

 

Cabinet sized specimen comprised mostly of golden green marcasite crystals although some calcite crystals (especially on the left side) are present.  For the size of the specimen, there is very little damage other than typical contacting especially on the back right corner where some calcites were cleaved.  Otherwise in great shape and a nice large hand sized specimen from this mine.  $75.00

 

Linwood 34:  Calcite on limestone:  24 x 20 x 9 cm (9.5 x 7.9 x 3.5 inches) - $150.00

 

 

Calcite on limestone:  Large cabinet specimen featuring several rhombohedral calcite crystals mainly between 1-2 cm on edge covering a limestone matrix base.  There are a few crystals up to 3 cm across as well.  As with many large specimens from this mine, there is some contacting (both from natural sources and as the result of mining - this specimen may have been in a fairly tight pocket as some limestone is present on the top as well and has left a few indentations or residue on some crystal faces).  Some typical small rubs on the edges are also present, but for a specimen of this size it is in much better shape than the majority of pieces that come out in this size.  $150.00

 

 

 

 

 

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