The Chemistry Behind the Crystal
Every mineral tells a story through its chemistry. At its core, OLGITE is defined by the chemical formula (Ba,Sr)(Na,Sr,REE)2Na(PO4)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. OLGITE 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: P3m1
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 OLGITE, the dimensions of this microscopic building block are:a=5.56Å, c=7.045Å, Z=1The internal arrangement of these atoms is described as:Phosphates, arsenates, vanadates: anions [PO4]3-, [AsO4]3-, [VO4]3- are usually insular; cations may be small with [4] coordination, medium-sized with [6] coordination, or large with [8] or higher coordination; medium-sized cations with octahedral [6] coordination may be insular, corner-, edge- or face-sharing & form major structural units with medium-sized & large cations; sheets of edge-sharing M[12] polyhedra & PO4 tetrahedra alternate with layers of M[10], M[8], M[6] polyhedra // (0001); 3 kinds of rods // (0001) connect layers; face-sharing M[12] polyhedra & Na[6] octahedra; edge- & corner-sharing M[10] polyhedra & PO4 tetrahedra; & M[6] octahedra & PO4 tetrahedra; glaserite-related structure.1 In xl structure, there is 1 tetrahedrally coordinated P site with
= 1.526 & 1.522 Å; there are 3 M sites: [12]-coordinated M(1) site is occupied primarily by Ca (with subordinate Sr & minor K) with
Physical Appearance (Habit)
When you find OLGITE in the field, what does it actually look like? A mineral’s “habit” describes its typical shape and growth pattern.- Common Habit: Hexagonal prismatic crystals, elongated; in rounded grains
- Twinning:
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 nepheline syenite pegmatite in 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. OLGITE is often related to other species, either through similar chemistry or structure.Relationship Data: Forms series with bari-olgiteUnderstanding 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 OLGITE?The standard chemical formula for OLGITE is (Ba,Sr)(Na,Sr,REE)2Na(PO4)2. This defines its elemental composition.2. Which crystal system does OLGITE belong to?OLGITE crystallizes in the Hexagonal-Trigonal system. Its internal symmetry is further classified under the Trigonal scalenohedral class.3. How is OLGITE typically found in nature?The “habit” or typical appearance of OLGITE is described as Hexagonal prismatic crystals, elongated; in rounded grains. This refers to the shape the crystals take when they grow without obstruction.4. In what geological environments does OLGITE form?OLGITE is typically found in environments described as: In nepheline syenite pegmatite in differentiated alkalic massif. This gives clues to the geological history of the area where it is discovered.5. Are there other minerals related to OLGITE?Yes, it is often associated with or related to other minerals such as: Forms series with bari-olgite.External Resources for Further Study
For those looking to dive deeper into the specific mineralogical data of OLGITE, we recommend checking high-authority databases:- Mindat.org – The world’s largest open database of minerals.
- Webmineral.com – Detailed crystallography and mineral properties.
- International Mineralogical Association (IMA) – The official list of approved mineral names.