I don't believe, not even for a moment, that there are "two
different" kinds of qamats.
The "rule" to the effect That
הברה סגורה לא מוטעמת שמנוקדת בקמץ -
רוב הסיכויים שזה קמץ קטן
is, in my opinion, not worth the ink spent to print it.
When we judge it expedient (this is possibly an ancient opposition to
some aspects of the Tiberias NIKUD) we predictably replace (we
override) the qamats by a xolam, say OREK - ORKO, ROXAB - ROXBO,
KTOBET - KTOBTIY, and many more.
I am not sure why XAKMAH (Yiddish: xoxme, as in: a groisse xoxme), is
pronounced XOKMAH, possibly because XOX sound better than XAX.
On the the hand we say CAHARAYIM, TAHARAH, MIMAXARAT (and not
MIMAXORAT. see Lev. 23:15) etc., to the great consternation of the
YIDONIYM who admonish us that we are in the wrong, as we subvert
their "rules".
You may want to look here http://www.saad.org.il/elihu/questions.html
for an example of the theological-gramatical quibbles arising from
the uncertainty of a gadol versus a qatan.
Isaac Fried, Boston University
On Jan 23, 2012, at 10:04 AM, Pere Porta wrote:
Do you then think that there is only a qamats which depending on
the place where it is placed has sound "a" or sound "o"? (the same
graphical sign to designate two different phonemes)