Minerals from the O'Neal Quarry, Plymouth, Hancock County, Illinois

The O'Neal (Plymouth) Quarry is located in eastern Hancock County, Illinois.  This quarry is probably best known for its fine calcite and quartz specimens but other minerals such as pyrite, sphalerite, and the nickel related minerals (millerite, polydymite) have also been found occasionally.  Collecting access to the quarry, like most other quarries in the Midwest, is extremely limited or virtually impossible due to increasing liability concerns and recently access was completely sealed off even to those few that had access.  Do expect regular postings of this material and availability at shows, however, as we were able to secure and stockpile specimens when access was possible.

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Plymouth 20:  Calcite on limestone:  3 x 2 x 3.5 cm (1.2 x 0.8 x 1.4 inches) - $4.00

 

Plymouth 21:  Calcite:  2.8 x 2 x 2.4 cm (1.1 x 0.8 x 0.95 inches) - $4.00

Small miniature sized specimen of intergrown calcites perched on a limestone base.  A few of the calcites have rubs on crystal edges and the smaller crystal on the left side of the specimen in the right photo has a cleave near the base of the edge of the crystal.  Damage overall, however, is quite minimal.  $4.00

 

Single rhomb of calcite with a smaller calcite crystal attached to the back of the main crystal.  The crystal is cleaved on the right side and a few minor scuffs on crystal edges here and there.  $4.00

 

Plymouth 03:  Pyrite and Marcasite on limestone:  10.5 x 7 x 2 cm (4.1 x 2.8 x 0.8 inches) - $25.00 sold

 

Plymouth 22:  Calcite on Quartz:  3.3 x 1.2 x 3.3 cm (1.3 x 0.5 x 1.3 inches) - $5.00 sold

Fine combination specimen from this quarry.  The limestone base is host to several initial growths of bladed and slightly iridescent marcasite.  Upon or in close association with the marcasite are cuboctahedral or cubic pyrites.  Some minor contacting in a few areas that is insignificant - this is one of few specimens of this type I have seen from this quarry over the years, especially with this association.  $25.00

 

 

Classic O'Neal Quarry material with a quartz coated limestone base and a single 1 cm (0.4 inch) calcite perched right on top.  Under 10x magnification there are a few little nicks to crystal edges on the calcite.  Quality small miniature sized specimen from this location.  $5.00

 

 

Plymouth 23:  Calcite:  6.5 x 5 x 3.5 cm (2.6 x 2 x 1.4 inches) - $8.00

 

Plymouth 24:  Calcite on limestone:  7.5 x 3 x 4 cm (3 x 1.2 x 1.6 inches) - $6.00

Blocky cluster of rhombohedral calcite crystals.  It was much more common to find calcite clusters in smaller sizes and when larger ones were encountered, it was difficult to remove them without damage.  The only damage to this specimen is some contacting to the back right portion and some slight contacting along the edges of the piece.  $8.00

 

 

A limestone base is host to a scattered cluster of calcite crystals, mainly in the upper left portion of the specimen.  The calcites range in size on edge from a few millimeters up to 2 cm (0.8 inches) across.  There is contact damage to the back of the right two crystals in the right image above and small nicks are barely visible on other major crystals.  Overall, however, when displayed as shown in the left photo, damage is not apparent.  The specimen could be trimmed a little more to create a nice miniature sized specimen.  $6.00

 

Plymouth 25:  Calcite on limestone:  7.5 x 7 x 2 cm (3 x 2.8 x 0.8 inches) - $7.00

 

Plymouth 08:  Calcite with limestone:  7 x 6 x 4 cm (2.8 x 2.4 x 1.6 inches) - $10.00

Several small calcites just a few millimeters across cover a limestone matrix base.  One larger crystal on the right side of the specimen (2.1 cm across, or just over 0.8 inch) dominates and just has little nicks along the edge under 10x magnification.  Nice small cabinet specimen from this location.  $7.00

 

 

Interesting specimen featuring nearly all calcite but with mixed forms.  The larger blocky crystals are in association with a couple of dogtooth (scalenohedral) crystals.  The more cubic crystals are up to 3 cm on edge (1.2 inches) with the scalenohedral crystals up to 2.8 - 3 cm (nearly 1.2 inches).  Very little damage - some contacting to the base and a few edge nicks on the larger crystal cluster but overall a nice calcite from this quarry.  $10.00

 

Plymouth 09:  Calcite on limestone:  6 x 5.5 x 3 cm (2.4 x 2.2 x 1.2 inches) - $6.00

 

Plymouth 26:  Quartz with Marcasite:  11 x 8.5 x 3.5 cm (4.3 x 3.35 x 1.4 inches) - $8.00 sold

Cluster of calcite crystals are found upon a limestone matrix base.  There is some contacting on the right side that does affect the overall value and displayability.  This is more of a reference specimen for the location - the largest calcite in the back is nearly 4 cm (1.6 inches) across, the main reason for inclusion on this page.  Some minor pyrite is in association.  $6.00

 

Rounded specimen of crystallized mostly milky quartz with a hint of marcasite at the left side of the specimen.  There seemed to be many more quartz specimens in the Plymouth quarry compared to nearby locations.  No damage.  $8.00 sold

 

 

Plymouth 11:  Calcite on limestone:  4.5 x 3.8 x 1.5 cm (1.8 x 1.7 x 0.6 inches) - $4.00

 

Plymouth 12:  Calcite:  3.5 x 3.5 x 3 cm (1.4 x 1.4 x 1.2 inches) - $6.00

Calcite crystals are found positioned on a small calcite covered limestone base.  The specimen was in a tight pocket, evidenced by limestone residue on the top of the highest calcite crystals.  Minor edge contacting is the only damage.  $4.00

 

Miniature sized cluster comprised mainly of two rhombohedral calcite crystals, each approximately 3-3.5 cm (1.2 to 1.4 inches) on edge.  As is typical of nearly all of these larger crystals, there are a few nicks here and there but overall a nice example from the location.  Minor limestone on the back.  $6.00

 

 

 

Plymouth 13:  Calcite on limestone:  4.5 x 3 x 2.5 cm (1.8 x 1.2 x 1 inches) - $5.00 sold

 

Plymouth 27:  Calcite on limestone:  8.2 x 6.5 x 1.5 cm (3.3 x 2.6 x 0.6 inches) - $10.00

Calcite crystals up to 3 cm (1.2 inches) are perched on a thin limestone matrix base.  The crystals exhibit good clarity especially at the terminations.  Some microscopic to minor edge rubs are seen to the main crystals - the extent of damage visible in the lower photographs.  $5.00

 

Nice small cabinet plate of calcite crystals from this quarry!  The calcites range in size from a few millimeters up to just over 2 cm (0.8 inch) across and the only damage is mainly tiny rubs or nicks on a few crystal edges and contacting to the sides of the specimen.  $10.00

 

Plymouth 15:  Calcite on limestone:  6 x 4.5 x 2.5 cm (2.4 x 1.8 x 1 inches) - $5.00

 

Plymouth 16:  Calcite:  8.5 x 7 x 3 cm (3.35 x 2.8 x 1.2 inches) - $7.00

Small crystals of calcite are present on a limestone matrix chunk.  Some cleaving/rubs are present especially on the back side but I cannot find much wrong on the main display side as shown here.  $5.00

 

Small cabinet sized cluster of calcite crystals.  There are cleaves and rubs on the edges of the specimen as the photos show - this is mainly just a good reference specimen for the location given the damage.  $7.00

 

Plymouth 28:  Calcite on limestone:  6.2 x 4.5 x 2.5 cm (2.5 x 1.8 x 1 inches) - $6.00

 

Plymouth 18:  Calcite on limestone:  6 x 4.2 x 3.7 cm (2.4 x 1.7 x 1.5 inches) - $5.00

A limestone matrix base is host to a single 2 cm (0.8 inch) calcite crystal and a few smaller but largely insignificant calcites along the perimeter of the specimen.  The very left bottom edge of the main crystal has a slight cleave but otherwise is damage free.  $6.00

 

 

A scattering of calcite crystals up to 2 cm (0.8 inches) - most are under 1 cm (0.4 inches) are present on a limestone matrix chunk.  Some minor rubs or nicks here and there but nothing major.  Typical specimen from the location.  $5.00

 

Plymouth 19:  Calcite on limestone:  6.5 x 3.5 x 2 cm (2.6 x 1.4 x 0.8 inches) - $6.00 sold

 

Plymouth 29:  Calcite on limestone:  9.5 x 5 x 2 cm (3.7 x 2 x 0.8 inches) - $10.00 sold

Rhombohedral calcite crystals up to 2 cm (0.8 inches) are perched on a limestone base.  Some edge contacting is present but overall the damage is minimal.  Nice calcite from this quarry.  $6.00

 

A limestone plate is host to a heavy complete coating of calcite crystals up to 2 cm (0.8 inches) across on edge.  There is some contacting/rubbing to the edges of the specimen but nothing atypical for these specimens.  $10.00 sold

 

 

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