Tuff in cactus mixes...?

[Steve Johnson]

Tom, here's an idea...

When in doubt, ask a geologist. If you contact the geology department of your local college or university, someone there may be able to help you describe the mineral you got from the Mono Lake area. Not sure if you'd want to drive there, but if you ship a small sample to them, I'm sure they'll give you an ID. And it wouldn't be a bad idea if you ask the geology folks a couple of questions -- what is the mineral's chemical composition, and do any of those chemicals react in water? If you follow through on my idea, I'd be interested to know about what you discover.

[keith]

mono lake I bet its volcanic around the lake but the soil in the lake bed itself ?

[Steve Johnson]

mono lake I bet its volcanic around the lake but the soil in the lake bed itself ?

Think I found out what the mineral is -- not tuff, not tufa, but tephra. Here's a quote from Wikipedia:

• "The most recent eruptive episode on the Mono Craters occurred sometime between the years 1325 and 1365. A vertical sheet-like mass of magma, called a dike, caused groundwater to explosively flash to steam, creating a line of vents 4 miles (6 km) long. A mix of ash and pulverized rock, called tephra, covered about 3,000 square miles of the Mono Lake region. The tephra were carried by the wind and deposited in a layer 8 inches deep 20 miles from the vents and 2 inches deep 50 miles away."

"This medium looked like Styrofoam pellets when it disintegrates, (but not as light weight)" -- sounds like Tephra. And because it disintegrates into volcanic soil, you'll find out why Tom was lucky to bring a bunch of it home:

https://www.scienceabc.com/nature/why-i ... rtile.html

Keith, if you ever get up to the Mono Lake area, you may want to bring some of it home with you too.

[Tom in Tucson]

mono lake I bet its volcanic around the lake but the soil in the lake bed itself ?

Think I found out what the mineral is -- not tuff, not tufa, but tephra. Here's a quote from Wikipedia:

• "The most recent eruptive episode on the Mono Craters occurred sometime between the years 1325 and 1365. A vertical sheet-like mass of magma, called a dike, caused groundwater to explosively flash to steam, creating a line of vents 4 miles (6 km) long. A mix of ash and pulverized rock, called tephra, covered about 3,000 square miles of the Mono Lake region. The tephra were carried by the wind and deposited in a layer 8 inches deep 20 miles from the vents and 2 inches deep 50 miles away."

"This medium looked like Styrofoam pellets when it disintegrates, (but not as light weight)" -- sounds like Tephra. And because it disintegrates into volcanic soil, you'll find out why Tom was lucky to bring a bunch of it home:

https://www.scienceabc.com/nature/why-i ... rtile.html

Keith, if you ever get up to the Mono Lake area, you may want to bring some of it home with you too.

Thank you Steve for all your suggestions and research.

I think you "nailed it". Now, if I can just find a way not to spend all that gas money for roughly the 1000 mile round trip + the time involved. Now that the name seems to be fully resolved, my serious searching can really begin in earnest!

I'll report back with my discoveries soon.

[Steve Johnson]

Glad I could help, Tom!

[MrXeric]

I just want to mention that tephra is the collective term for all material that is ejected into the air during a volcanic explosion. This includes things like volcanic ash, scoria, and pumice. Tuff is just volcanic ash that's been lithified over time. What Tom found is probably weathered scoria (or lapilli if small enough), especially if found near a cinder cone (cinder is just another name for scoria).

Some links:
https://en.wikipedia.org/wiki/Tephra
https://www.nps.gov/subjects/volcanoes/pyroclasts.htm
https://geology.com/rocks/scoria.shtml

[keith]

Flagstaff has weather volcanic soil . Probably other places in AZ also ? Owens valley where mono lake is has lots of interesting volcanic geology.

[Tom in Tucson]

Flagstaff has weather volcanic soil . Probably other places in AZ also ? Owens valley where mono lake is has lots of interesting volcanic geology.

You are correct. I'm trying to find a source for any bagged tephra, I've come to the tentative conclusion that I must gather it from a source where there has been suitable volcanic activity in the last few million years. If you "Google" "Tephra in Arizona", the Flagstaff region is what is the first "hit". It appears that the region where such mineral deposits can be found in the USA is bounded from the Yellowstone region - west to the Pacific NW - south to the Mono Lake region, (where my discovery was) and then southeast to around Flagstaff.

Before I do any field collecting of tephra, I'm going to keep "Googling" for any retail source, but I'm likely going to have to gather it myself from near a cinder cone.

[Tom in Tucson]

I just want to mention that tephra is the collective term for all material that is ejected into the air during a volcanic explosion. This includes things like volcanic ash, scoria, and pumice. Tuff is just volcanic ash that's been lithified over time. What Tom found is probably weathered scoria (or lapilli if small enough), especially if found near a cinder cone (cinder is just another name for scoria).

Some links:
https://en.wikipedia.org/wiki/Tephra
https://www.nps.gov/subjects/volcanoes/pyroclasts.htm
https://geology.com/rocks/scoria.shtml

Thank you for your additional geologic descriptions. In my search for any source on line, I may use the various names you have provided.

[keith]

Azomite ? " Azomite 44 lbs Micronized Organic Trace Mineral Soil Additive Fertilizer ' never used it but have seen it at garden centers it says its volcanic dust.

[Nino_G]

In my understanding zeolite is a form of tuff. I use zeolite as a part of my mineral substrate mixtures for a long time with excellent result. Some european growers use pure zeolite as a growing medium for seedlings with very good results. Zeolite has very high CEC (Cation Exchange Capacity) which enables plants to utilize water and nutrients in much more stable manner.

[C And D]

Tuff = Pumice

Tuff is compacted pumice

It abounds around Mono Lake, and I as well have collected the pumice there, since it is easy to collect and already clean
All from the violent eruptions of the local volcanos
I used to ride my Mt. Bike down steep slopes of pure pumice nearby, it was like skiing.

There are typically 2 types of volcanism, basalt or granitic,
Geologists have better names for these
Granitic volcanism form pumice and obsidian when cooled fast, and granite when cooled slowly