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GLG Mineralogy
United States
Registrace 4. 01. 2021
Mineral Identification : Staurolite and Andalusite
Luster - vitreous, sub vitreous, earthy
Streak - NA, harder than streak plate
Hardness - 6.5-7.5
Density - moderately dense
Cleavage - poor
Color - earthy tones, browns, black
Crystal system - andalusite = orthorhombic, staurolite = monoclinic
Crystal form/habit - staurolite perfect euhedral crystals, andalusite blocky and tabular
Extra notes - grey cross on andalusite formed by interstitial graphite (chiastolite), staurolite is commonly twinned (cruciform twinning)
Streak - NA, harder than streak plate
Hardness - 6.5-7.5
Density - moderately dense
Cleavage - poor
Color - earthy tones, browns, black
Crystal system - andalusite = orthorhombic, staurolite = monoclinic
Crystal form/habit - staurolite perfect euhedral crystals, andalusite blocky and tabular
Extra notes - grey cross on andalusite formed by interstitial graphite (chiastolite), staurolite is commonly twinned (cruciform twinning)
zhlédnutí: 3 688
Video
Mineral Identification : Sillimanite and Kyanite
zhlédnutí 4,7KPřed 3 lety
Luster - vitreous, (sillimanite sometimes earthy if weathered) Streak - white Hardness - sillimanite 7, kyanite variable hardness with orientation 4.5-7 Density - moderately dense Cleavage - sillimanite = perfect in 1 direction, Kyanite = perfect in 2 directions Color - white to variable, kyanite displays much stronger colors Crystal system - kyanite = triclinic, sillimanite = orthorhombic Crys...
Mineral Identification : Olivine
zhlédnutí 10KPřed 3 lety
San Carlos Olivine Mantle Xenolith Nodules Luster - vitreous Streak - NA, harder than streak plate Hardness - 6.5-7 Density - moderate to moderately low Cleavage - none, conchoidal fracture Color - green Crystal system - orthorhombic Crystal form/habit - rarely in euhedral crystals Extra notes - color varies with Fe content, very brittle
Mineral Identification : Garnets
zhlédnutí 7KPřed 3 lety
Almandine | Pyrope | Spessartine | Grossular Luster - Vitreous Streak - NA, too hard Hardness - variable, 6.5-7.5, scratches glass Density - moderate to moderately low density, almandine the densest, grossular least dense Cleavage - none, conchoidal fracture Color - highly variable! Crystal system - isometric Crystal form/habit - euhedral high symmetry ball forms Extra notes - can often be foun...
Mineral Identification : Sorosilicates and Cyclosilicates
zhlédnutí 4KPřed 3 lety
Beryl | Epidote | Tourmaline Luster - Vitreous Streak - white, if not harder than the streak plate Hardness - beryl (7.5-8), tourmaline (7-7.5), epidote (6-7) Density - moderately low Cleavage - imperfect or poor, epidote is perfect in one direction Color - variable! Beryl = pale colors, tourmaline highly variable and often bicolored, epidote = pistachio green Crystal system - beryl (hexagonal)...
Mineral Identification : Amphiboles
zhlédnutí 16KPřed 3 lety
Hornblende | Tremolite | Actinolite | Glaucophane Luster - vitreous Streak - white, if not harder than the streak plate Hardness - 5-6 Density - moderately dense Cleavage - two perfect planes at 56 and 124 degrees Color - hornblende = black, tremolite- actinolite defined by green variability, glaucophane is noticeably grey blue Crystal system - monoclinic Crystal form/habit - bladed, fibrous, e...
Mineral Identification : Pyroxenes
zhlédnutí 9KPřed 3 lety
Diopside | Augite | Enstatite | Jadeite Luster - vitreous to sub vitreous Streak - white, or too hard to powder Hardness - 5.5-7 Density - moderately low Cleavage - two good angles at ~90 degrees Color - variable but usually green, brown, black Crystal system - monoclinic (enstatite = orthorhombic) Crystal form/habit - euhedral crystals (jadeite = polycrystalline) Extra notes - jadeite tends to...
Minerals : Phyllosilicates - Talc
zhlédnutí 5KPřed 3 lety
Luster - pearly Streak - white Hardness - 1 Density - low density Cleavage - NA Color - white, pale, pastels Crystal system - monoclinic Crystal form/habit - massive, blocky, fibrous Extra notes - soft to the touch, silky
Minerals : Phyllosilicates - Biotite, Muscovite, Lepidolite, Chlorite
zhlédnutí 9KPřed 3 lety
Luster - vitreous Streak - white, very pale brown (biotite) Hardness - 3-4 Density - moderately low Cleavage - perfect 1 direction, parallel sheets Color - variable, black (biotite), white (muscovite), pink/lavender (lepidolite), green (chlorite) Crystal system - monoclinic Crystal form/habit - sheets, books, pseudo-hexagonal Extra notes - we mainly use color to distinguish
Minerals : Phyllosilicates - Kaolinite
zhlédnutí 6KPřed 3 lety
Luster - earthy Streak - white Hardness - 2-2.5 Density - very low density Cleavage - NA Color - white Crystal system - triclinic Crystal form/habit - massive, blocky Extra notes - readily powder-able
Mineral : Phyllosilicates - Serpentine
zhlédnutí 11KPřed 3 lety
Luster - pearly, earthy, vitreous, waxy Streak - white Hardness - highly variable Density - moderately low Cleavage - NA Color - green, yellow, brown Crystal system - monoclinic Crystal form/habit - fibrous, blocky, massive, layered Extra notes - fibrous and potentially dangerous, heavily altered
Mineral : Tectosilicates - Plagioclase Feldspars
zhlédnutí 6KPřed 3 lety
Luster - vitreous Streak - white Hardness - 6-6.5 Density - moderately low density Cleavage - two planes @ 90 degrees Color - variable, white-grey-dark, labradorescence Crystal system - triclinic Crystal form/habit - blocky, massive Extra notes - you can expect visible lamallae that are very straight, and a play of colors in labradorite
Mineral : Tectosilicates - Alkali Feldspars
zhlédnutí 12KPřed 3 lety
Luster - vitreous, sub vitreous Streak - white Hardness - 6-6.5 Density - moderately low density Cleavage - two planes at 90 degrees Color - variable, beige-blue-pink-off white Crystal system - orthoclase = monoclinic, microcline = triclinic Crystal form/habit = orthoclase = euhedral, microcline = massive/blocky Extra notes - look for exsolution in microcline
Mineral :Tectosilicates - Opal
zhlédnutí 1,2KPřed 3 lety
Luster - vitreous Streak - white Hardness - 5-6 Density - low density Cleavage - none Color - variable Crystal system - amorphous Crystal form/habit - forms in veins and pockets Extra notes - conchoidal fracture, internal light diffraction produces a play of colors
Minerals : Tectosilicates - Quartz
zhlédnutí 3,4KPřed 3 lety
Luster - Vitreous Streak - white Hardness - 7 Density - moderatley low Cleavage - none Color - variable, usually pale colors Crystal system - hexagonal Crystal form/habit - polycrystalline, terminated hexagonal prism, microcrystalline Extra notes - conchoidal fracture
"and really, color is what does it for the amphiboles." That could not be more true in my world! I've been collecting nephrite in Wyoming for decades, and color is what makes the difference between the best emerald and apple green jade and a lump of uninspiring olive or sage green.
No danger in displaying them as-is. In a small, plastic case to prevent dust; The fibrous minerals have a beauty all their own.
Thank you for your video series. I've watched a lot and find yours is one of the best
Have a calcite
Any mineral with density < 1 ?
Galena ?
Thank you. Lonsdaleite necheral Diamond par caret HOW much sir
This was super informative and easy to follow. Thank you for sharing your knowledge 😊
Spessartine is best garnet..❤
I've found a lot of Olivene here in Wyoming.
It looks like Chrysoprase to me
Is it quartz chalcedony?
Kaolinite is not chalk - please correct your video.
Hi
i have chalcopyrite and i want to know if it real
hi
If you can dissolve a sample, perhaps in Nitric Acid and if the mineral contains Copper then you will get a blue solution - then Copper will be confirmed if on adding aqueous ammonia you get a very intense blue solution. You might also try sulphuric acid to get it to dissolve.
hi
Price
Holy cow that’s a cancer cocktail! How could you not mention asbestos?
Yes, I had the same thought. We should also be discussing nephrite jade in this group!
Thank you for a well done video and easy to understand.
what is the benefits of this stone
what is the benefits of this stone
Thank you. Interesting!
How to dissolve graphite? Any process ?
Great information. Your videos short, direct to the point. Subscribed! If you can also do the mix specimen samples as well. Or same crystal around the world example amethyst. How and why different colors, which is more preferable, different qualities. Example how to know AAA quality and museum quality pieces.
Thankyouvary much
I just found an area with lots of garnets 😊 I think there almandine but not sure
Thank you for that, it's helped greatly :):).
Good speaking voice, thanks for sharing your knowledge
If you run it through a electro magnet will it hold onto its magnetism as in would even temporarily become a magnet in other words can you make a permanent magnet out of magnetite ?
Great information, I’ve been finding some pieces around on hikes but none like that faceted one! I found a nice semi flat piece and want to carve or shape a pendant some how..any suggestions?
Pourquoi en anglais On est en France
I love your videos thank you.
i love them all just dug some perthite from old Perth quarry
This seems like quite a good mineral to carve high detail microcarvings on due to the low hardness and apparent lack of chipping flaking. Do you know of any other low hardness minerals that would be good for this sort of work? Thanks for the informative video!
Good question! Gypsum is soft enough to scratch by hand, but any mineral below a 7 on Moh's hardness scale would be easily scratched/etched with simple tools.
@@GLGMineralogy Thanks! the microcarver I know only works with things Mohs 4 and below, as his carvings have detailing that is literally microscopic and it is hard to hand carve such details accurately at higher hardness. That obviously restricts the options quite a bit compared to having options from Mohs 5 to 7. Still, it seems like Gypsum at least is quite a nice material for this =)
It's an experiment to see the reaction of calcite, right? calcium carbonate
Excellent 👍 thank you
Thank you too!
Thanks for the info, my friends house is made of the clear stuff
Plutonium... no, no! Asbestos 🤓 ...nailed it. That time that student never came back after midterms .
Thank you, you make sense
Nice crystal of pyrite - I only ever found cubes! A marcasite sample had me fooled for years...
There is also the black variety known as "blackjack" and has an adamantine lustre.
Very helpful video - thanks! It's also crumbly and often smells slightly of sulphur, more so than pyrite. The crystal form is the key.
Ola.Estou curiosa para saber se achei uma Amazonita?Encontrei numa praia uma pedra verde com uma espécie de capa brilhosa semelhante a está cor de salmão que Vce mostrou.Mas a pedra tem formato triangular e uma base piramidal com um acabamento em zigzag na textura Toda ela reflete brilho prateado cinza .Mas parece ser rodeada por linha de crescimento do cristal ou então trata-se de fedspato? Gostaria muito de lhe mostrar em vídeo. Aqui uns dizem que é Amazonita.Outros dizem que não por conta da textura da pedra que difere da pedra Amazonita. Vce tem como ajudar?
Halite?
Wow a YT video that is science based and not some sales pitch bs or esotheric delusion.
This video is very helpful for me ❤
Do your sample fluoresce?
Very well explained.. thanks for sharing your knowledge
What does olivine turn into? What is serpentinization❤️
I get a kick out of how everyone seems to assume that only specimens freshly delivered from matrix need be described for field i.d. At around 150 m.y.o. these rascals have plenty of time to get all alluvial wit it and are fond of hanging out at the beach surfing, bullying the locals and often doing a very passable impression of jade, jasper, and late stage "wtf happenned to my compound hardness?" kyanite Dont be too surprised to pull a glitteringly smoothed kyanite "fan" from the surf that seems to be literally birthing a bouncing baby corundum pseudomorph. God I love rocks.