Almandine schorl and sillimanite locality, Haddam, Middlesex County, Connecticut, USAi
| Regional Level Types | |
|---|---|
| Almandine schorl and sillimanite locality | - not defined - |
| Haddam | Town |
| Middlesex County | County |
| Connecticut | State |
| USA | Country |
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Latitude & Longitude (WGS84):
41° 28' 19'' North , 72° 30' 39'' West
Latitude & Longitude (decimal):
Köppen climate type:
Nearest Settlements:
| Place | Population | Distance |
|---|---|---|
| East Haddam | 9,042 (2017) | 4.7km |
| Higganum | 1,698 (2017) | 4.7km |
| Moodus | 1,413 (2017) | 6.1km |
| Chester Center | 1,558 (2017) | 9.3km |
| East Hampton | 2,691 (2017) | 11.5km |
Nearest Clubs:
Local clubs are the best way to get access to collecting localities
Local clubs are the best way to get access to collecting localities
| Club | Location | Distance |
|---|---|---|
| Lapidary and Mineral Society of Central Connecticut | Meriden, Connecticut | 26km |
| New Haven Mineral Club | New Haven, Connecticut | 39km |
| Bristol Gem & Mineral Club | Bristol, Connecticut | 43km |
Williams (circa 1945) writes: "Sillimanite, Garnet, and Tourmaline with splendid terminations translucent of a dark brown color, occur one hundred yards east of the Killingworth Road near the Norman Spencer house." Evidently, based on his accompanying map, the "Killingworth Road" is Jail Hill Road (not what we now know as state Rt. 81). His map places the locality between Jail Hill Rd. and the quarries on top of Great Hill, the coordinates, based on this, are approximate. However, London (1989) maps a small body of rock in this precise area he called "mfs", which is a muscovite-feldspar schist containing accessory tourmaline, garnet up to 30% and sillimanite commonly as large prisms, fibrolitic mats and nodules with quartz. Based on analyses of typical schist and gneiss hosted garnets in Connecticut, the species is almost certainly almandine. The tourmaline is very likely schorl, based on the black color and absence of Mg minerals in the schist matrix.
Select Mineral List Type
Standard Detailed Gallery Strunz Chemical ElementsDetailed Mineral List:
| ⓘ Almandine Formula: Fe2+3Al2(SiO4)3 Habit: dodecahedral Colour: burgundy Description: Crystals to 1.5 cm weathering out of schist matrix. Species ID based on XRD analyses by Harold Moritz of many schist and gneiss-hosted garnet porphyroblasts in Connecticut, which showed them to be all almandine. |
| ⓘ Schorl Formula: NaFe2+3Al6(Si6O18)(BO3)3(OH)3(OH) Habit: short prismatic Colour: black Description: "with splendid terminations translucent of a dark brown color" Williams (circa 1945). Species ID based on black color and lack of Mg minerals in the schist. |
| ⓘ Sillimanite Formula: Al2(SiO4)O Description: as aggregates in nodules in schist |
Gallery:
List of minerals arranged by Strunz 10th Edition classification
| Group 9 - Silicates | |||
|---|---|---|---|
| ⓘ | Almandine | 9.AD.25 | Fe2+3Al2(SiO4)3 |
| ⓘ | Sillimanite | 9.AF.05 | Al2(SiO4)O |
| ⓘ | Schorl | 9.CK.05 | NaFe2+3Al6(Si6O18)(BO3)3(OH)3(OH) |
List of minerals for each chemical element
| H | Hydrogen | |
|---|---|---|
| H | ⓘ Schorl | NaFe32+Al6(Si6O18)(BO3)3(OH)3(OH) |
| B | Boron | |
| B | ⓘ Schorl | NaFe32+Al6(Si6O18)(BO3)3(OH)3(OH) |
| O | Oxygen | |
| O | ⓘ Almandine | Fe32+Al2(SiO4)3 |
| O | ⓘ Schorl | NaFe32+Al6(Si6O18)(BO3)3(OH)3(OH) |
| O | ⓘ Sillimanite | Al2(SiO4)O |
| Na | Sodium | |
| Na | ⓘ Schorl | NaFe32+Al6(Si6O18)(BO3)3(OH)3(OH) |
| Al | Aluminium | |
| Al | ⓘ Almandine | Fe32+Al2(SiO4)3 |
| Al | ⓘ Schorl | NaFe32+Al6(Si6O18)(BO3)3(OH)3(OH) |
| Al | ⓘ Sillimanite | Al2(SiO4)O |
| Si | Silicon | |
| Si | ⓘ Almandine | Fe32+Al2(SiO4)3 |
| Si | ⓘ Schorl | NaFe32+Al6(Si6O18)(BO3)3(OH)3(OH) |
| Si | ⓘ Sillimanite | Al2(SiO4)O |
| Fe | Iron | |
| Fe | ⓘ Almandine | Fe32+Al2(SiO4)3 |
| Fe | ⓘ Schorl | NaFe32+Al6(Si6O18)(BO3)3(OH)3(OH) |
Other Regions, Features and Areas containing this locality
North AmericaContinent
North America PlateTectonic Plate
- Ganderia DomainDomain
- GranderiaPassive Margin
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