If you are fascinated by the hidden structures of our planet, you have likely come across
ERICSSONITE. This mineral is a compelling subject for study, offering a unique glimpse into the complex chemistry that shapes the Earth’s crust.Whether you are a student identifying a hand sample, a researcher looking for crystallographic data, or a collector curious about a new find, this guide breaks down everything you need to know about
ERICSSONITE. From its precise chemical formula to the geological environments where it thrives, let’s explore what makes this mineral distinct.
The Chemistry Behind the Crystal
Every mineral tells a story through its chemistry. At its core,
ERICSSONITE is defined by the chemical formula
BaMn2+2Fe3+[Si2O7]O(OH).This isn’t just a string of letters and numbers; it represents the precise recipe of elements that nature used to build this specimen. This specific chemical composition is what gives the mineral its stability and dictates how it reacts with acids, heat, or other minerals. It is the fundamental “DNA” that geologists use to classify it within the larger mineral kingdom.
Crystallography: Geometry in Nature
One of the most beautiful aspects of mineralogy is the hidden geometry within every stone.
ERICSSONITE crystallizes in the
Monoclinic system.Think of this as the mineral’s architectural blueprint. It dictates the symmetry and the angles at which the crystal faces grow. Digging deeper into its symmetry, it falls under the
Prismatic.
- Point Group: 2/m
- Space Group: C2/m
Why does this matter? These crystallographic details are like a fingerprint. They influence optical properties—how light travels through the crystal—and physical traits like how it breaks or cleaves when struck.
Internal Structure and Unit Cell
If we could zoom in to the atomic level, we would see the “Unit Cell”—the smallest repeating box of atoms that builds up the entire crystal. For
ERICSSONITE, the dimensions of this microscopic building block are:
a=20.46Å, b=7.03Å, c=5.34Å, ß=95.5o, Z=4
The internal arrangement of these atoms is described as:
Sorosilicates: SiO4 tetrahedras combined mainly in pairs, also in larger combos which form isolated grp; Si2 O7 grp with add’l anions, cations in octahedral [6] &/or other coordination; chains // [001] of edge-sharing BaO8 polyhedra crosslinked into sheets // by edge-sharing CaO6 octahedra & Si2O7 grp; dimers of edge-sharing ZrO6 octahedra linked into undulating chains // [001] by TiO6 octahedra.3 HOH layer is main structural unit in xl structures of Fe3+—disilicates ericssonite—2O, ideally Ba2Fe3+2Mn4(Si2O7)2O2(OH)2, ferroericssonite, ideally Ba2Fe3+2Fe2+4(Si2O7)2O2(OH)2, & yoshimuraite, ideally Ba4Ti2Mn4(Si2O7)2(PO4)2O2 (OH)2, T5-block mineral of Grp II; chemical compositions of core part of HOH layer in ericssonite—2O & ferroericssonite, [5]Fe3+2Mn4(Si2O7)2O2(OH)2 & [5]Fe3+2Fe2+4(Si2O7)2O2(OH)2, are similar to chemical composition of core part of HOH layer in yoshimuraite, [5]Ti2Mn4(Si2O7)2O2(OH)2, except for cation species at [5]—coordinated MH site in H sheets: [5]Fe3+ & [5]Ti, resp; despite this similarity, topology of HOH layer in ericssonite—2O & ferroericssonite is diff from that in yoshimuraite; in T5-block minerals, diff distortions of MO octahedra correspond to specific types of linkage of H & O sheets; topological consideration of Fe3+— disilicates ericssonite—2O & ferroericssonite & yoshimuraite, TS—block mineral of Grp II, shows that diff topologies of chemically identical HOH layer are due to diff in bond—valence contributions of Fe3+ & Ti at MH site in H sheet (i.e., inability of Fe3+ to contribute sufficient bond—valence to XOM anion) & subsequenent diff distortions of MO octahedra in O sheet, where MO = Mn2+, Fe2+.This internal structure is the invisible framework that supports everything we see on the outside, from the mineral’s density to its hardness.
Physical Appearance (Habit)
When you find
ERICSSONITE in the field, what does it actually look like? A mineral’s “habit” describes its typical shape and growth pattern.
- Common Habit: As radiating macro crystals
- Twinning:
Twinning is a fascinating phenomenon where two or more crystals grow interlocked in a specific symmetrical pattern. If ERICSSONITE exhibits twinning, it can be a dead giveaway for identification, distinguishing it from look-alike minerals.
Where is it Found? (Geologic Occurrence)
Minerals are the products of their environment. They don’t just appear anywhere; they need specific conditions—pressure, temperature, and chemical ingredients—to form.
Geologic Occurrence:
In thin veins in nepheline syenite pegmatites in a differentiated alkalic massifKnowing this context helps geologists reconstruct the history of a rock formation. It tells us whether the rock was born from cooling magma, settled in an ancient ocean, or was transformed by the intense heat and pressure of metamorphism. For more broad geological context, resources like the
U.S. Geological Survey (USGS) provide excellent maps and data.
Related Minerals
No mineral exists in a vacuum.
ERICSSONITE is often related to other species, either through similar chemistry or structure.
Relationship Data:
Lamprophyllite group; dimorphous with orthoericssonite (obsolete=polytype); compare rosenbuschite groupUnderstanding these relationships is key. It helps us see the “family tree” of the mineral world, showing how different elements can substitute for one another to create an entirely new species with similar properties.
Frequently Asked Questions (FAQs)
1. What is the chemical formula of ERICSSONITE?The standard chemical formula for ERICSSONITE is
BaMn2+2Fe3+[Si2O7]O(OH). This defines its elemental composition.
2. Which crystal system does ERICSSONITE belong to?ERICSSONITE crystallizes in the
Monoclinic system. Its internal symmetry is further classified under the Prismatic class.
3. How is ERICSSONITE typically found in nature?The “habit” or typical appearance of ERICSSONITE is described as
As radiating macro crystals. This refers to the shape the crystals take when they grow without obstruction.
4. In what geological environments does ERICSSONITE form?ERICSSONITE is typically found in environments described as:
In thin veins in nepheline syenite pegmatites in a differentiated alkalic massif. This gives clues to the geological history of the area where it is discovered.
5. Are there other minerals related to ERICSSONITE?Yes, it is often associated with or related to other minerals such as:
Lamprophyllite group; dimorphous with orthoericssonite (obsolete=polytype); compare rosenbuschite group.
External Resources for Further Study
For those looking to dive deeper into the specific mineralogical data of
ERICSSONITE, we recommend checking high-authority databases:
Final Thoughts
ERICSSONITE is more than just a name on a list; it is a testament to the orderly and beautiful laws of nature. With a chemical backbone of
BaMn2+2Fe3+[Si2O7]O(OH) and a structure defined by the
Monoclinic system, it holds a specific and important place in the study of mineralogy.We hope this overview has helped clarify the essential data points for this specimen. Whether for academic study or personal interest, understanding these properties brings us one step closer to understanding the Earth itself.
