To me, jewels=jewelry. Now let's define jewels.
Aw that’s easy
Jewels are cut stones 
Well that’s what I was taught.
Regards Charles A.
When does a non-wearable ornament like this transition into an objet d'art worth millions?
Art is a very subjective topic. And imo, very silly sometimes.
Something is art when you say it is.
For a piece of art to be worth millions, requires the artist to deem
it so, and to have someone willing to pay for it.
Look at this
The last line from the article:-
"A similar work by the same artist has sold for more than $1m.
Equivalent VIII was on show at the Royal Academy earlier this
month in its Modern British Sculpture exhibition."
We had a painting come through where I work part-time. The value was
$50,000, and no one wanted to work on it for fear of damaging it
even slightly. The funny thing was that this painting was done for a
friend at half price. Personally I couldn’t see the value in it. The
artist has a name, hence the price reflects this.
Art is very subjective.
Regards Charles A.
P.S. I’m going out to buy 120 bricks set it up and feel like I’ve got a
million dollar art installation 
She can correct me if I am wrong Charles but I saw no “wearable” in
the Oxford definition. Perhaps then one could talk about wearable and
non-wearable jewellery but this was discussed previously on Orchid.
Sto:lo people here make wooden wearable masks which can become quite
valuable to art collectors. I am trying to purchase machinery which
would allow us to replicate them in stone. Jewellery?
To me, jewels=jewelry. Now let's define jewels
Well, since you asked, (do I sense another eternal thread…) to me,
cholla cactus wood and beach pebbles are jewels.
Vicki K, SoCal
P.S. I'm going out to buy 120 bricks set it up and feel like I've got a million dollar art installation :-D
Wow! I bought 150 bricks and call it a sidewalk.
Bobbie Horn
Already replied off list, but “personal ornament” is the key phrase,
you sit on, not wear, an ornamental piece of furniture.
Regards Charles A.
Jewel = something small, precious, and eye-catching like a dewdrop
in the sun, or a star in the night sky.
Ornament = anything that adorns, including jewels.
Thus jewelry is automatically an ornament, but an ornament is not
always a jewel. ‘Art’, ‘Artisan’, and ‘Design’, are means to an end.
Alastair
If jewelry carries a criterion of wearability, what do we say about
what royalty have worn over the ages? Helmets and crowns and
breastplates, boots, belts, buckles and swords and shielding into
war; clothing with precious metals and stones built into it on
ceremonial occasions. Even gold and jewel encrusted caskets in death.
Is all this jewelry?
M
Perhaps there is a bit of “overthinking” the topic, here.
Historically, when you look at things like wardrobe accounts, wills
and the like, they made a fairly sharp distinction between "jewels"
and items that were “bejeweled”.
There was some overlap. Things like crowns and buckles would fall
into the “jewelry” camp when they got elaborate enough.
Ron Charlotte
Gainesville, FL