If you are fascinated by the hidden structures of our planet, you have likely come across
DELINDEITE. 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
DELINDEITE. 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,
DELINDEITE is defined by the chemical formula
Ba2Ti2(Na2□)Ti[Si2O7]2(OH)2O2(H2O)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.
DELINDEITE 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/c
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
DELINDEITE, the dimensions of this microscopic building block are:
a=10.645Å, b=13.713Å, c=21.600Å, ß=93.80o, Z=8
The internal arrangement of these atoms is described as:
Sorosilicates: SiO4 tetrahedras combined mainly in pairs, also in larger combos which form isolated grp; Si2O7 grp with add’l anions, cations in octahedral [6]± coordination.2 Ideally octahedral (O) sheet sandwiched btw 2 heteropolyhedral (H) sheets which are formed by Ti-octahedra & disilicate grp [Si2O7]; O sheet comprises large (Na,K) polyhedron together with octahedral Na & Ti sites; alkali polyhedra are partially vacant; large Ba cation is localized in interlayer; evidence of leaching of alkalis; this series is considered of mero-plesiotype; heterophyllosilicate HOH layer, to 1st ±, module in this series, whereas interlayer content is variable (merotypism), & may modify its structure in diff members (plesiotypism).3 Block 1 consists of HCH sheets (H = heteropolyhedral, C=central) & related to TS block in Ti disilicate minerals; in TS block, 7 fully occupied cation sites, 4 [4]-coordinated Si sites with 1.622Å & 3 [6]-coordinated Ti-dominant sites; M(1) & M(2) coordinated by 5 O atoms & 1 OH grp, 1.974 Å; they give Ti1.88 Nb0.07Al0.05 M(3) site, Ti0.82 Fe3+0.12 Nb0.06, coordinated by 4 O atoms & 2 OH grp, 1.964 Å; 4 partially occupied sites: Na(1) & Na(2) sites occupied by Na with minor Fe2+ & Mn2+ at 70%, 2.31 Å; [8]-coordinated Na(3) site, Na0.70□0.30 , & [7]-coordinated K site, K0.18□0.82 , 2.90 Å, at short distance, 1.25 Å; M(1,2) octahedra & Si2O7 grp constitute H sheet, long-range ordered; in C sheet, M(3) octahedra & H2O grp [O (19)], ordered, Na(1-3) & K atoms & 3 H2O grp, 50% occupancy, long-range disordered; some short-range order; 2nd (intermediate) I block incl [10]-coordinated Ba(1) & Ba(2) sites of, Ba0.92K0.08, Ba1.00, 2.961 & 2.873 Å; HCH & I block, is layer of Ba atoms, alternate along c.4 See “Additional Structures” tab for entry(s).5This 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
DELINDEITE in the field, what does it actually look like? A mineral’s “habit” describes its typical shape and growth pattern.
- Common Habit: As lath-shaped crystals or flakes, forming compact spherulitic aggregates
- Twinning: Submicroscopic on {100}, common
Twinning is a fascinating phenomenon where two or more crystals grow interlocked in a specific symmetrical pattern. If DELINDEITE 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 vugs and miarolitic cavities, as a weathering product of titaniferous nepheline syeniteKnowing 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.
DELINDEITE is often related to other species, either through similar chemistry or structure.
Relationship Data:
Bafertisite group; compare hejtmaniteUnderstanding 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 DELINDEITE?The standard chemical formula for DELINDEITE is
Ba2Ti2(Na2□)Ti[Si2O7]2(OH)2O2(H2O)2. This defines its elemental composition.
2. Which crystal system does DELINDEITE belong to?DELINDEITE crystallizes in the
Monoclinic system. Its internal symmetry is further classified under the Prismatic class.
3. How is DELINDEITE typically found in nature?The “habit” or typical appearance of DELINDEITE is described as
As lath-shaped crystals or flakes, forming compact spherulitic aggregates. This refers to the shape the crystals take when they grow without obstruction.
4. In what geological environments does DELINDEITE form?DELINDEITE is typically found in environments described as:
In vugs and miarolitic cavities, as a weathering product of titaniferous nepheline syenite. This gives clues to the geological history of the area where it is discovered.
5. Are there other minerals related to DELINDEITE?Yes, it is often associated with or related to other minerals such as:
Bafertisite group; compare hejtmanite.
External Resources for Further Study
For those looking to dive deeper into the specific mineralogical data of
DELINDEITE, we recommend checking high-authority databases:
Final Thoughts
DELINDEITE 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
Ba2Ti2(Na2□)Ti[Si2O7]2(OH)2O2(H2O)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.
