Lepidolite Mica Mineral ID'd #shorts

Lepidolite Mica Mineral ID'd #shorts

This #shorts video features the mineral, lepidolite–using photogrammetry. Lepidolite is a mica mineral. It is similar in structure to muscovite and biotite. However, lepidolite is a light purple or lavender color, where biotite is black and muscovite is a clear/translucent colorless. However, lepidolite is a bit harder than biotite and muscovite–with a hardness similar to your fingernail (about 2.5-3.0 on Mohs’ hardness scale).

Lepidolite is relatively easy to identify because of the distinctive mica structure and distinctive lavender color. Like many mica minerals, there is an obvious layering –and it can split/cleave more easily between the individual layers, than through the individual layers. This preferential layering/orientation is called a “cleavage”. Lepidolite is considered to have a “good” cleavage (actually if often splits so well along between the layers, that is called “perfect” cleavage.

Lepidolite is a major source for lithium. The lavender color of lepidolite is from the manganese part of its composition (the color is not because of the lithium). It is an uncommon mineral.

Hello Rock People! This is Dave the Geology Dude. Identification notes are below in this text. Note that I have other videos that provide more rock identification information on my YouTube channel. But this video is meant as a quick way to view rock samples without distractions (from on-screen text or voiceovers). It is best to try to see many examples of the same rock type–because only then you understand the range of variables that can be associated with each rock type. Also, be aware that the only way to really learn rock identification, is to have hands-on experience. This is because visual experiences alone do not show the physical properties that can range in variables– and are common to each rock type. Note: if you don’t like the music on this video, you can always turn off the sound and watch with your own music instead. Don’t forget that: Geology isn’t Rocket Science–it’s Rock Science!

Identification information for this rock:
1) Environment: lepidolite is found in pegmatites, and related minerals of spodumene
2) Shape/cleavages: Lepidolite is very similar to biotite and muscovite. All are in the mineral group called “micas”, The structure to micas are like tightly stacked thin “sheets” (or very thin layers–that are almost paper-thin)–like packs of paper stacked within Post-It Notes collection of individual sheets. Micas usually can be split into individual or packs of sheets–by hand (often with the initial help of prying apart with your fingernails). Yes, you can break these rocks with only your fingers. These micas have cleavages–which is a distinct layering structure–that will preferentially split/cleave between this layering structure. Note that the individual sheets of mica–after separating into individual sheets–often can be flexed or bent slightly by your fingers, without damaging the sheet-like structure of the mineral. But it is possible to break through the individual sheets by hand–if you try to rip/fold the individual sheets.
3) Color–Lepidolite is shiny transparent to translucent–with a light purple color. Although it may have some color variables–such as red, yellow, and colorless.
4) density–density is slightly more than most other rocks (2.8-3.0 times water)
5) hardness–it is only 2.5-3.0 on Mohs’ hardness scale. It will not scratch glass (but may leave a powder/flakes on the glass because the glass instead will be abrading the rock–as you try to scratch the glass with it).
6) streak– lepidolite really does not leave a streak
6) acid reactivity: will not react to acid contact
7) luster–has a nonmetallic glassy (or vitreous) luster.
8) often confused with muscovite and biotite–because these micas form into similar structures of layered, thin flat sheets. But biotite is consistently dark black in color, and muscovite is either colorless, or a transparent/translucent light-gray or a faint/subtle tan/yellowish-gray in color.
9) Summary: lepidolite is a shiny transparent to translucent mineral–with a nonmetallic glassy luster. It has a light-purple or lavender color, and is about as hard as a fingernail. This mineral forms tightly packed sheets like in a Post-It Note pad (often called “books). Similar to Post-It Note pads, the strength along the individual sheets of lepidolite, is much more stronger (harder to break) than the bonds between the individual sheets. That is why it is much more easier and predictable that sheets in a Post-It Note pad will separate cleanly from the “pad” (or “book” of sheets), than to break or tear within the individual sheets.

Music (YouTube Audio Library): Help Me, OP-1 (by Dyalla)

Copyright by David Knoblach, 2022. All rights reserved (please contact me for permission to use).