FMF - Friends of Minerals Forum, discussion and message board

[Tobi]

I mentioned before that i was collecting olivine for many years near my hometown. There was one really exceptional find that i want to share with you. When i showed it to fellow collectors in Germany they were stunned and they assured me that a olivine crystal of that size is very unsual for Europe. These olivines are grown in the basalt on a former military training area a few kilometers away from Marburg (Northwestern Hesse). One day, it is three years ago, i picked up a piece of basalt and turned it around ... that's what my eyes saw after the cleaning. The crystal has a lenght of 20 mm and is completely transparent.

[Peter]

Very nice crystal and in nice contrasting matrix too!
There are some wonderful olivine which were found primarily in the 1950-60s in Norway (Almklovdalen) but large crystals are rare. I have a gemmy 4 cm crystal, of which some 2.5 cm is flawless and could cut a large stone. Of course I keep it as a specimen! But unlike yours, it has no matrix. Thanks for showing it Tobias!

[Tobi]

A 4 cm gem crystal of olivine? Wow, please show it!

These olivines from the basalt near Marburg are usually not that big and gemmy. I was collecting them for 5 years or so, and i always found just the ordinary clusters of crystals, the biggest of them about 4 mm. One day i found my second-best one, a single crystal of 18 x 11 x 7 mm, but it was broken and weathered. Yes, and then there was this one ... i couldn't believe my eyes when i held it in my hands.

[Peter]

Guten abend

I do not have this specimen where I am now. Will try to remember to make a snapshot and post for you!

[Andreas Gerstenberg]

I kinda know this sweety. Oh, I really think I do...

[Tobi]

You do. It's the one we already discussed on mineralienatlas.de some time ago ...

[Jason]

That is sweet..color looks fantastic..well done Tobias..do you have a pic of a regular or standard find from that location

[Tobi]

My last answer was so dumb, sorry: I forgot that this specimen was the one i sold to Andreas and which is now in his collection :D

Amethystguy, i will try to take photos of some average specimen from there tomorrow.

[Tobi]

[Tobi]

... but the other 0,1 percent are really good (for central-European olivine).

I made two real good finds: The one with which i started the thread and which now is in Andreas Gerstenberg's collection, and this one here. It measures 50 x 30 x 18 mm at all and the "large" crystal measures nearly 1 cm.

And this is but a fragment of a former, larger single crystal that - according to the visual cavity in the basalt and to the measures of its fragments - must have had a size of 18 x 12 x 9 mm. Brilliant for a European olivine, but broken and weathered long time ago.

[Jason]

LOL..compared to the norm, the good ones you found are like night and day..well done Tobias!!!!

[Antonio Alcaide]

Universal law of crystals and finds: "If a find provides thousands of small crystals one can find one or two big ones at least". It's a matter of chance -and effort-. Tobias' olivines are the proof.

Cheers

[Tobi]

That's right, Antonio. I don't know how many field trips i went on to look for olivines, but i think i was there maybe a dozen times or so and i only found these two large crystals. And if you say that it needs a thousand disappointments to succeed once: I think turned around and picked up about at least 2000 rocks to find that two good ones, so your calculation was right ;-)