Hi agent z
Someone really seems interested in crystallography!
Another great translation! I have made some minor changes below; please let me know whether you agree.
Eulytite is one of the rarest minerals
in nature. It occurs as a single crystal*,
an assembly** of crystals
or maybe better: assemblies of crystals and radially fibrous spherulites***. Crystals usually have a tetrahedral appearance. Two sides are mainly developed, sometimes one, seldom 5.
Crystal appearance of eulytite from
the Shneeberg field.
*maybe better: single crystal
s
**Possible alternative: aggregates
*** I don't know anything about spherulites - in fact, I had never heard the word! But I think in geology, this is referred to as radially fibrous spherulites. See http://www.nps.gov/history/history/online_books/geology/publications/rpt/7-1/contents.htm for an image
In English, I think the second sentence would normally describe plural forms (crystals, aggregates etc) and not singulars. If you do prefer singulars, you will need an article (
a crystal).
As for the last sentence, it looks like this may be a description or legend for an image. Do you think that might be the case? I have based my sentence on this assumption.
There is one sentence I don't understand. Do you know what is meant by this one?
Two sides are mainly developed, sometimes one, seldom 5.
The English looks fine, I just don't understand what it means - but maybe this will make perfect sense to a mineralogist!