Rocks & Minerals & Fossils
As I assume is made abundantly clear by the website name, background, cursor and icons, I am a geologist. From this revelation naturally follows the fact I am prone to geeking out about my marvellous menagerie of minerals... and rocks and also fossils.
The purpose of this page is twofold. One, it benefits me as a "formal" catalogue of my collection. For each of my specimens I will give it an ID and identify its traits to the best of my ability. Two, it benefits me again as a really good excuse to ramble about how cool rocks are.
Like the gallery, specimen thumbnails have been compressed so that the page loads more quickly. As usual each specimen can be clicked on to view a larger size along with the associated details.
Last Updated: 01/02/25
Minerals
Specimen Qualities
- ID: #1
- Species: Amethyst
- Weight: Unknown
- Locality: Unknown
- Age: Unknown
General Qualities
- Class: Silicate
- Hardness: 7
- Habit: Prismatic
- Cleavage: N/A
- Fracture: Conchoidal
- Colour: Violet
- Streak: White
- Lustre: Vitreous
- Specific Gravity: 2.65
- Other: Piezoelectric
Notes
Amethyst is easily one of the most well-known minerals and probably the one you're most likely to have even if you're not a rock collector.
Technically, amethyst isn't a mineral in its own right as it is actually a variety of quartz. The violet colour is the result iron impurities in the lattice. Therefore, amethyst maintains many qualities of quartz, it's chemical resilience and hardness, that make it popular as a gemstone for jewellery.
Specimen Qualities
- ID: #3
- Species: Pyrite
- Weight: Unknown
- Locality: Unknown
- Age: Unknown
General Qualities
- Class: Sulphide
- Hardness: 6-6.5
- Habit: Cubic
- Cleavage: N/A
- Fracture: Conchoidal
- Colour: Brassy-yellow
- Streak: Greenish-black
- Lustre: Metallic
- Specific Gravity: 5
- Other: Paramagnetic
Notes
"Fool's gold" is the infamous alternate name of pyrite, plaguing hopeful prospectors for centuries.
Pyrite is captivating because it's one of the few minerals that can form truly perfect cubic crystals, unfortunately my sample is much more of an anhedral mass of many crystals.
Rocks
Specimen Qualities
- ID: #2
- Species: Quartz Monzonite
- Weight: Unknown
- Locality: Shap Fell, Cumbria, UK
- Age: Devonian
General Qualities
- Type: Igneous
- Composition: Felsic
- Depth: Intrusive
- Texture: Porphyritic crystalline
- Other: N/A
Notes
I originally mistook this specimen for a pink granite, but the identification it came with describes it as a monzonite. It turns out it's a very similar rock in terms of formation, texture and composition that has a lower proportion of quartz. Granite has 20% quartz or more, a monzonite only has 5-20%.
Specimen Qualities
- ID: #4
- Species: Quartz Monzonite
- Weight: Unknown
- Locality: Unknown
- Age: Unknown
General Qualities
- Type: Igneous
- Composition: Ultramafic
- Depth: Mantle
- Texture: Coarse-grained
- Other: Greer
Notes
Peridotite dominates the composition of the upper regions of Earth's mantle and is thus directly inaccessible to us. So, the reason samples of it are even obtainable is because peridotite is often brought up to the surface as an inclusion in basalt lavas, as partial melting of the mantle results in a mafic magma. The black at the top of the sample (not the small crystals) is basalt.
Fossils
Specimen Qualities
- ID: #5
- Species: Flexicalymene Trilobite
- Weight: Unknown
- Length: 6.5cm
- Width: 4.5cm
- Locality: Erfoud, Morocco
- Age: Ordovician
General Qualities
- Phylum: Arthropod
- Class: Trilobita
- Temporal Range: Mid-Ordovician - Mid-Silurian
- Other: Commonly found enrolled
Notes
Trilobites are probably my favourite animal and will be intensely familiar to anyone whose had a palaeontology lesson.