Calcite from Rucks’ Pit
Okeechobee County, Florida, USA
To see the largest single plate of calcified Mercenaria permagna clams ever recovered from Rucks’ Pit, click on the picture to the right. This piece measures 35 x 25 x 6.9 inches (89 x 63.5 x 17.5 cm), and is home to over 40 Mercenaria clams.
The specimens depicted below come from a relatively new find of gemmy honey-amber calcite crystals filling and replacing Mercenaria permagna clams. First discovered by Dr. Thomas Scott of the Florida Geological Survey, the clams are found in living position, and are largely confined to a stratigraphic zone 0.3 – 0.6m thick throughout the pit. Because these Mercenaria are found in hinge-up living position, it has been suggested that they died in place due to a catastrophic event, such as sudden burial or freshwater poisoning resulting from a hurricane, tsunami or other causes. The age of these Mercenaria fossils is late Pliocene to early Pleistocene (1 – 1.5 million years old).
The
size of the crystals (to over 3 cm in length) and the occurrence of many
complete articulated crystal-filled clams make this occurrence unique. In all
crystal-bearing specimens, a portion of the sides (and sometimes tops) of the
clam shells have been dissolved by ground water. This creates “natural windows”
into each clam, allowing the internal crystallization to more easily be seen.
The largest crystal clusters grow downward from the hinge area (top) of the
clams. When found broken away from the rest of the fossil clam, these hinge
pieces make outstanding thumbnail to small cabinet - sized crystal specimens.
The
calcite from this site fluoresces a light yellow-green color under shortwave and
longwave UV light, and also phosphoresces for a second or two once the black
light is extinguished.
This site produces other calcified pelecypods, including Busycon rucksorum (Whelk), Anadara (Ark shells), and others. Most calcite crystals within these mollusks are drusy, and lack the deeper color and transparency of the larger crystals found growing within Mercenaria permagna clams.
Rucks’ Pit is an active mine, being worked primarily for limerock used for road base material. The stratigraphic zone being mined for aggregate is the same horizon in which the calcified Mercenaria occur.
Through an
agreement with the owner, Apalachee Minerals and The Fossil Geode
had exclusive commercial collecting privileges at this site, collecting from 2003-2005.
The Fossil Geode's
web site has additional photos of this site.
If you are interested in
purchasing any of these minerals, or if you have a question, you can place
your order on on our secure
ORDER
FORM. You will need to know the specimen number, the specimen
name and the price.
If you have any questions, feel free to
CONTACT US.
Please click on Thumbnail Photos to view larger image and more details on each mineral.
SEE CALCITE CLAMS IN MATRIX DOWN BELOW
OR click here to go straight to the MATRIX page
 |
 |
 |
 |
|
CAL0414-
$200 (c) |
CAL2494-
SOLD (c) |
CAL2753-
$40 (c) |
CAL3065- $50 (c) |
 |
 |
 |
 |
|
CAL3100-
$200 (c) |
CAL3103-
$180 (lc) |
CAL3104-
$220 (c) |
RUC2033-
$120 (c) |
 |
 |
 |
 |
|
RUC2828-
$140 (c) |
RUC2866-
$190 (c) |
RUC2868-
$148 (c) |
RUC2870-
$270 (c) |
 |
 |
 |
 |
|
RUC2873-
$165 (c) |
RUC2888-
$104 (c) |
RUC2897-
$100 (c) |
RUC2968-
$76 (c) |
 |
 |
 |
 |
|
RUC2971-
$120 (c) |
RUC2973-
$110 (c) |
RUC3033-
$76 (sc) |
RUC3037-
$58 (c) |
 |
 |
 |
 |
|
RUC3317-
$88 (c) |
RUC3468-
$220 (c) |
RUC3681-
$76 (c) |
RUC3683-
$78 (c) |
 |
 |
 |
 |
|
RUC3684-
$96 (sc) |
RUC3689-
$84 (c) |
RUC3706-
$120 (c) |
RUC3708-
$38 (sc) |
 |
 |
 |
 |
|
RUC3801-
$56 (c) |
RUC3802-
$56 (sc) |
RUC3807-
$58 (sc) |
RUC4035-
$180 (lc) |
 |
 |
 |
 |
|
RUC4387-
$80 (c) |
RUC4417-
$80 (c) |
RUC4421-
$38 (m) |
RUC4448-
$42 (sc) |
 |
|||
|
RUC4449-
$180 (lc) |
Calcite in Matrix from Rucks’ Pit
Okeechobee County, Florida, USA
Please click on Thumbnail Photos to view larger image and more details on each mineral.
CAL2508- $420 CAL2518 - $500
CAL3101- $420 RUC2432 - $245
RUC2794- $220 RUC3567- $180
RUC4037- $260
Thumbnail (t)
3 cm or smaller
Miniature (m) 3 – 6 cm
Small Cabinet (sc) 6 – 8 cm
Cabinet (c) 8 - 12 cm
Large cabinet (lc) > 12 cm