Crystal Question

Actually, crystal is glass that contains lead. ;)

vj found this in rec.crafts.beads, from "CLP" :

]there's something ]different in the composition,

lead content

----------- @vicki [SnuggleWench] (Books)

Actually, crystal is glass that contains lead. ;)

not all crystal contains lead - only "lead" crystal contains lead....

PS - if you own a lead crystal decanter - do NOT store beverages in it.... it does leach.... Cheryl of DRAGON BEADS Flameworked beads and glass

vj found this in rec.crafts.beads, from snipped-for-privacy@aol.combeads (Cheryl) :

]not all crystal contains lead - ]only "lead" crystal contains lead....

okay - i thought to be "crystal" it had to be lead crystal. so what's the difference between non-lead crystal and glass?

----------- @vicki [SnuggleWench] (Books)

vj found this in rec.crafts.beads, from snipped-for-privacy@aol.combeads (Cheryl) :

]it's a complex answer - but as close as I can get you.....

thanks, Cheryl!

----------- @vicki [SnuggleWench] (Books)

]only "lead" crystal contains lead....<

Which is why vintage crystals are so heavy - they're leaded.

Carol in SLC JustBeads Auctions:

On Sun, 31 Aug 2003 1:20:23 -0400, vj wrote (in message ):

vj found this in rec.crafts.beads, from Kathy N-V :

Rock crystal is uncolored quartz. Most white sand is also made of quartz. Isn't sand used to make glass?

:o)

Arondelle

To muddy the waters even further, there is also a mineral form of clear crystal which is cut and made into beads. And, many other minerals and stones have a crystalline structure: after all, a diamond is merely the crystalline form of carbon.>

Yeah - and I HAVE A STRAND OF THEM that belonged to my great aunt!!!

Cheryl of DRAGON BEADS Flameworked beads and glass

Rock crystal is uncolored quartz. Most white sand is also made of quartz. Isn't sand used to make glass?>

yup - I didn't go there (to muddy the waters further).... but in scientific glassblowing - the most PURE form used is quartz glass. It is nearly pure quartz MELTED like glass. Because it is so pure it requires extremely high temperatures (and is also dangerous to the eyesight and health of the glassworker - as heating it that hot gives off dangerous levels of IR and UV... and gaseos byproducts that can damage the lungs - special eyewer and respiratory equipment is used when working quartz crystal glass.) Pure SILICA SAND is the purest form of sand for high quality glass making.

Common "sand" is often quartz with impurities (commonly iron)....and what causes the green in your Coke Bottle.... (iron makes green, as well as some copper) the mixing of sand and other elements in the "batch" (glassmaker's term for the recipe mix of chemicals) is aimed at producing clarity and color (or lack there of) it's a interesting scientific artform. I have some sample "batch" glass recipes if you would like to see some... if I can find them... LOL

Cheryl of DRAGON BEADS Flameworked beads and glass

And quartz is silica in a crystalline form. So, silica glass is made of the same stuff that quartz is. :o)

Arondelle

vj found this in rec.crafts.beads, from snipped-for-privacy@aol.combeads (Cheryl) :

]actually "crystal" IS any clear, colorless class.

so my clear, colorless, drinking glasses are CRYSTAL? who knew?

i'm going to have to be more careful than ever shopping for beads, tho!

----------- @vicki [SnuggleWench] (Books)

On Sun, 31 Aug 2003 11:04:53 -0400, CLP wrote (in message ):

A lovely thought, but probably not. Some of the characteristics of Down's are incompatible with life; cardiac problems, for example. The most damning of these characteristics is the inability to learn quickly and adapt -- ancient man had to learn and adapt quickly or die. A baby with Down's typically requires more care than one without, which makes it harder for that characteristic to be passed on, on an evolutionary level. After all, even "normal" children died at a phenominal rate. Only the very strongest survived to pass along their genetic material.

If one of our prehistoric forebears had Down's, it is highly unlikely that s/he would have survived long enough to have children, and pass along his/her genertic material. In the event that a Down's person did live long enough to procreate, it's not a given that the children of such a union would have Down's, even if both parents had Down's. It makes little sense to assume that the non-Down's offspring wouldn't survive to procreate, and only the Down's offspring would.

It's a really neat thought to consider that there could have been a race of gentle people, all with the physical features that we associate with Down's. Sadly, nature is harsh, and such a race would almost certainly be doomed before it even formed. Our prehistoric forebears were in a constant struggle to survive, and such a gentle people probably wouldn't be up to the task.

Just my $0.02,

Kathy N-V

Regular glass is made of random molecules(?), in crystal glass the molecules are organized in rows. I think that is why good crystal glass makes that nice ringing tone when you flick them with your finger. With quartz and other rocks when the molecules line up they produce the crystal type structures. Just my 2 cents. I don't think it helps with the bead question much.

Oh, and for what it's worth, Swarovski is not famous primarily for its beads but for its larger pieces of optical glass. The lenses they make for telescopes weigh many tons!!!

Tina

I think they made the lenses for Mt Palomar.

Tina

Interesting... :-) I did not know that! Thanks for the tidbit.

What famous telescopes use Swarovski lenses?

Katra

Christ>

The Hale telescope lens at Mt Palomar was made by the Corning Company, Corning, New York. One of the failed pourings of the special borosilicate glass is (or was) on display in their Museum - a place ALL glass lovers should pilgrimage to at least once in their lives. I've been lucky enough to have visited once as a child, and because of the fascination born of that experience, I made sure I went once as an adult. I'd love to go back yet again because I'm sure I'd have even greater appreciation of the collection now.

Here's the page on the Hale telescope lens from their website: