If you are fascinated by the hidden structures of our planet, you have likely come across
FRANKHAWTHORNEITE. 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
FRANKHAWTHORNEITE. 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,
FRANKHAWTHORNEITE is defined by the chemical formula
Cu2(Te6+O4)(OH)2.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.
FRANKHAWTHORNEITE 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: P21/n
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
FRANKHAWTHORNEITE, the dimensions of this microscopic building block are:
a=9.10Å, b=5.21Å, c=4.60Å, ß=98.7o, Z=2
The internal arrangement of these atoms is described as:
Cation coordinations varying from [2] to [10] & polyhedra linked in var ways; OH’s (w/o V or U); chains of edge-sharing octahedra; edge-sharing TeO4(OH)2 octahedra & doublets of Cu(O,OH)6 octahedra form ribbons //[010]; ribbons are linked into framework by sharing corners of octahedra, creating □ open channels // [010].1 Structure analysis determined valence state of Cu2+ & Te6+ & # of O & (OH) anions in formula; consists of framework of edge-sharing octahedra; in hexagonal closest packed (HCP) array of anions, ½ of octahedrally coordinated sites are filled; unique topology of filled cation sites gives rise to ribbon of alternating [TeO4(OH)2]2- & double [CuO4(OH)2]8- octahedra.2 Nesotellurium Oxysalt: has O atoms forming slightly distorted hcp array with close-packed layers || (002); Cu & Te atoms occupy octahedral intersices to form ribbons in which 1 Te atom alternates with 2 Cu along y direction; ribbons form centered rectangular array, & share corners with their neighbors; Jahn-Teller distortion of Cu coordination polyhedron is similar degree to (Cu—O=4 x 1.98-2.06 Å & 2 x 2.46-2.52 Å), so only 4 shortest bonds are counted when defining structural unit, which is hence not framework but layer || (101); component ribbons of layer have each Te octahedron sharing 2 opposite edges with CuO4 □, & ribbons are linked thru CN3 O atoms in stepped pattern; Jahn-Teller distortion also reduces symmetry to monoclinic P21/n from orthorhombic Pmnn, & allows ordering of H atom on O2, as shown by long Te—O bonds (1.99 Å rather than 1.91—1.92 Å); layers are held together by long Cu….O bonds & H—bonds; similar array of more regular octahedra is found in borate kotoite.3 See “Additional Structures” tab for entry(s).4This 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
FRANKHAWTHORNEITE in the field, what does it actually look like? A mineral’s “habit” describes its typical shape and growth pattern.
- Common Habit: Stubby micro crystals, bladed and prismatic
- Twinning:
Twinning is a fascinating phenomenon where two or more crystals grow interlocked in a specific symmetrical pattern. If FRANKHAWTHORNEITE 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:
Secondary mineral formed by the oxidation of primary Cu-Te bearing sulfidesKnowing 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.
FRANKHAWTHORNEITE is often related to other species, either through similar chemistry or structure.
Relationship Data:Understanding 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 FRANKHAWTHORNEITE?The standard chemical formula for FRANKHAWTHORNEITE is
Cu2(Te6+O4)(OH)2. This defines its elemental composition.
2. Which crystal system does FRANKHAWTHORNEITE belong to?FRANKHAWTHORNEITE crystallizes in the
Monoclinic system. Its internal symmetry is further classified under the Prismatic class.
3. How is FRANKHAWTHORNEITE typically found in nature?The “habit” or typical appearance of FRANKHAWTHORNEITE is described as
Stubby micro crystals, bladed and prismatic. This refers to the shape the crystals take when they grow without obstruction.
4. In what geological environments does FRANKHAWTHORNEITE form?FRANKHAWTHORNEITE is typically found in environments described as:
Secondary mineral formed by the oxidation of primary Cu-Te bearing sulfides. This gives clues to the geological history of the area where it is discovered.
5. Are there other minerals related to FRANKHAWTHORNEITE?Yes, it is often associated with or related to other minerals such as:
.
External Resources for Further Study
For those looking to dive deeper into the specific mineralogical data of
FRANKHAWTHORNEITE, we recommend checking high-authority databases:
Final Thoughts
FRANKHAWTHORNEITE 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
Cu2(Te6+O4)(OH)2 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.
