If you are fascinated by the hidden structures of our planet, you have likely come across
REEVESITE. 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
REEVESITE. 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,
REEVESITE is defined by the chemical formula
Ni6Fe3+2(OH)16(CO3)·4H2O.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.
REEVESITE crystallizes in the
Hexagonal-Trigonal 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
Trigonal scalenohedral.
- Point Group: 3 2/m
- Space Group: R3m
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
REEVESITE, the dimensions of this microscopic building block are:
a=3.08Å, c=22.77Å, Z=3/8
The internal arrangement of these atoms is described as:
Carbonates contain planar trig complexes [CO3] with add’l anions with H2O; brucite-like layers // (0001) of edge-sharing octahedra of divalent & trivalent cations alternate with layers containing H2O molecules & charge-balancing anion, as in manasseite, but diff layer sequence; M2+:M3+ = 4:2.2 3 grp of double OH minerals are typified by pyroaurite & sjögrenite (now as pyroaurite-2H), hydrocalcumite, & ettringite; all show interesting structural features; in pyroaurite-sjögrenite grp (now hydrotalcite grp), brucite-like layers carrying net + charge alternate with layers in which O atoms of carbonate grps & H2O molecules are statistically distributed on single set of sites; hydrocalumite also have layer structures in which + charged main layers alternate with intermediate layers containing anions & H2O molecules; anions occur in cavities & their nature can again vary widely ( previous grps are now members of Hydrotalcite SG); in ettringite grp, structures are based on + charged columns, btw which occur channels containing anions & sometimes also H2O molecules; this grp incl thaumasite, only natural mineral known to contain Si [6]-coordinated by O that is not high-pressure phase.3This 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
REEVESITE in the field, what does it actually look like? A mineral’s “habit” describes its typical shape and growth pattern.
- Common Habit: Equant or prismatic hexagonal crystals (-2H); hexagonal tabular crystals (-3T)
- Twinning:
Twinning is a fascinating phenomenon where two or more crystals grow interlocked in a specific symmetrical pattern. If REEVESITE 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 carbonatite (-2H); in intrusive alkalic gabbro-syenite complex(-3T)Knowing 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.
REEVESITE is often related to other species, either through similar chemistry or structure.
Relationship Data:
Hydrotalcite supergroup, hydrotalcite group; (CO3) – analog of honessiteUnderstanding 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 REEVESITE?The standard chemical formula for REEVESITE is
Ni6Fe3+2(OH)16(CO3)·4H2O. This defines its elemental composition.
2. Which crystal system does REEVESITE belong to?REEVESITE crystallizes in the
Hexagonal-Trigonal system. Its internal symmetry is further classified under the Trigonal scalenohedral class.
3. How is REEVESITE typically found in nature?The “habit” or typical appearance of REEVESITE is described as
Equant or prismatic hexagonal crystals (-2H); hexagonal tabular crystals (-3T). This refers to the shape the crystals take when they grow without obstruction.
4. In what geological environments does REEVESITE form?REEVESITE is typically found in environments described as:
In carbonatite (-2H); in intrusive alkalic gabbro-syenite complex(-3T). This gives clues to the geological history of the area where it is discovered.
5. Are there other minerals related to REEVESITE?Yes, it is often associated with or related to other minerals such as:
Hydrotalcite supergroup, hydrotalcite group; (CO3) – analog of honessite.
External Resources for Further Study
For those looking to dive deeper into the specific mineralogical data of
REEVESITE, we recommend checking high-authority databases:
Final Thoughts
REEVESITE 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
Ni6Fe3+2(OH)16(CO3)·4H2O and a structure defined by the
Hexagonal-Trigonal 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.
