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[Hobbyprospect]

Dear all,

I am a Hobby prospector and I found this object in the river.
The specific gravity is 2.58 and I was not really able to scratch it with quartz so I think its slightly harder than quartz.
I found it in Czech Republic. Please see my pictures and tell me your opinion
One important thing to note is the flat side that looks almost like cut off was not cut by me. I found it like that which adds to the mystery.
It has a different feel not like quartz, also I see no fissures inside or cracks as often in gemstones

[Hobbyprospect]

One more picture

[alfredo]

The appearance clearly shows that this is chalcedony. Depending on how picky you want to be, it may or may not have enough banding to also be called "agate", but chalcedony for sure, not a tektite.

[Roger Warin]

Hi,
Tektites are rocks melted by the impact of a large meteorite.
For this, the components of the rock must be fusible, without going through a dissolution in hydrothermal water like chalcedonies and agates.
Feldspars often meet this criterion. The most beautiful tektites are moldavites (found in Moldova, a region known today) and they were ejected by a simultaneous and close double impact whose large crater is located in Ries in Germany, between Munich and Nuremberg. From there they flew towards Moldova. From memory, they traveled about 250 km.
The composition obviously depends on the composition of the impacted rocks.
This phenomenon is not so common.
The texture of a tektite is that of glass. There are never any microcrystals.

[Hobbyprospect]

Thanks a lot to everyone

[Riccardo Modanesi]

Hi to everybody!
By seeing these photos I can say it's an agate. I found many of them in Idar-Oberstein, even along the forest paths around the town.
Greetings from Italy by Riccardo.