Peter I always read your posts with great attention and am better
informed as a result. I must ask this: On the particular question of
photographing opal are you speaking from personal experience?
In my experience of photographing opal If the opal is properly cut
and polished it doesn't need any enhancing for photography. That
being said, I've found opal the most difficult stone there is to
photograph. I've given pieces to professional jewelry photographers
to shoot, with poor results and at considerable expense.
Photographers I've dealt with seem to be looking at the metal and
ignoring the stone as do show jurors.
[An aside: it annoys me to no end that when appling to juried shows I
get no credit for the lapidary work. Is lapidary less skillful than
metal work in jewelry? There usually is a separate metals category;
jewelry is often a combination of metal and stone.]
But I digress. Back to the photography: As a result of my experience
with photographers I've learned to do it myself. Since I cut the
opal I'm more familar with it's qualities and color than the
photographer who tends to ignore the stone and ignore the fact that
it must be lit differently than the metal.
I once had an offline conversation with David Barzilay about
photographing opal suggesting that he take two shots of the same
piece, lighting the stone differently, mask the stone in the shot
made for the metal and paste in the shot made for the stone. One
must have perfect registration for this to work. This method works
beautifully for all stones. Photoshop of course.
Mineral oil is fine, if you wish, for storage of uncut opal rough.
Won't prevent or in any way affect future crazing of the opal, but
won't hurt it either, in MOST cases.
This thing about oil and opal perpetuates a fiction. Some don't want
to pay the price and try ways to make the opal rough they buy better
than it is by oiling epoxying, etc. Perhaps the "silk purse from a
sow's ear" metaphor applies here. Often buyers don't want to pay the
price for quality material. Opal is the most expensive stone in the
world except for fancy colored diamonds.
I can't recall a piece of rough crazing for any reason; I attribute
this to buying quality from knowledgeable dealers. I live at 6850
feet elevation in NM, beautiful but very dry (yesterday 12%
humidity). All my opal is stored dry. I've not had a problem.
For those who want to pursue the matter of play of color in opal and
other opal matters: "A Field Guide to Australian Opals" by Barrie
O'Leary is a fine reference.
my reference to Barry O'Leary's book might be misconstrued. I
didn't intend it to be a comment in any on Mr. Wise's book
which I haven't read. Mr O'Leary's book on opal is very through
and was one of the first serious books on opal that I