To the OP: your best bet is to check futures prices. Platinum’s traded at NYMEX while Titanium is supposedly traded at the LME, but I couldn’t find anything on their web site. I believe that Platinum’s more expensive.
I wasn’t talking about titanium as a purified metal… I spoke of titanium the element, which is found in ALL of its compounds. This does get kinda confusing to me.
But IMO it doesn’t make sense to speak of an element as ‘man-made’ if all we’ve done is to refine it out of stuff that was already there in the earth. The only truly man-made elements are the ones that were developed through nuclear operations.
(Come to think of it, even elements such as plutonium we can’t say for sure do not exist naturally. We can say that they have not been discovered to pre-exist us on the planet earth. 
)
By a huge factor. Platinum is a precious metal currently selling for $800 - $900 an ounce (troy). You will not find titanium in precious metals listings because it is an industrial metal sold by the pound or ton. Expensive enough to be used only for speciality applications but more on the order of a few dollars a pound than hundreds of dollars an ounce.
(current spot price for platinum is quoted at $846/oz as I write. I can’t find a good current quote for titanium, but a number of sources list prices for titanium sponge in recent years as $3 or 4/lb).
I suspect it’s advertising of things like “titanium” credit cards as a level above platinum that leads to public perception concerning the value of titanium.
whoops, sorry scm1001, I missed your price quote.
In the same way, the titanium rings that have been coming out recently create the idea in consumers’ minds that titanium is even more special, more rare, than platinum. For my money, plain old sterling looks better than platinum or titanium.
Actually, we can be sure that Plutonium pre-existed us on the planet earth. Trace amounts of Plutonium can be found in naturally occuring uranium ores, where the Plutonium is created by irradiation with neutrons which are naturally present. However, Plutonium wasn’t discovered and isolated as an element until 1940, and then it was made by deuteron bombardment of Uranium. Cite.
In fact, quite a few of the Actinides occur in nature, while others are purely synthetic. Here is an overview;
[sub]90[/sub]Th: Thorium. Found in nature, discovered 1828 by Berzelius
[sub]91[/sub]Pa: Protactinium. Found in nature (part of [sup]238[/sup]U decay series), discovered in 1913
[sub]92[/sub]U: Uranium. Found in nature (for instance in pitchblende). First isolated 1841
[sub]93[/sub]Np: Neptunium. Trace quantities found in nature due to transmutation reactions in uranium ores. First identified 1940.
[sub]94[/sub]Pu: Plutonium. Again, trace quantities found in uranium ores. First identified 1940
[sub]95[/sub]Am: Americium. Not found in nature. First produced in 1944.
[sub]96[/sub]Cm: Curium. Theoretically could exist in uranium ores, but never detected. First produced 1944.
[sub]97[/sub]Bk: Berkelium. Not found in nature. First produced in 1949.
[sub]98[/sub]Cf: Californium. Not found in nature. First produced in 1950.
[sub]99[/sub]Es: Einsteinium. Not found in nature. First identified 1952.
[sub]100[/sub]Fm: Fermium. Not found in nature. Firsdt identified 1952.
[sub]101[/sub]Md: Mendelevium. Not found in nature. First identified 1955.
[sub]102[/sub]No: Nobelium. Not found in nature. First identified 1958.
[sub]103[/sub]Lr: Lawrencium. Not found in nature. First identified 1961.
So, you see that of the trans-uranium actinides, two exist in nature (Neptunium and Plutonium) and one theoretically should (Curium).
One of the reasons I know some of this stuff so well, is because I actually did some post-graduate work at the GSI (Gesellschaft fuer Schwerionenforschung) in Darmstadt (the heavy ion accelerator is actually located in Weiterstadt, which is an incorporated suburb of Darmstadt). Workgroups at the GSI are actually responsible for creating a couple of nuclei of [sub]108[/sub]Hs (Hassium), (named after the state of Hessia, where Darmstadt is), [sub]109[/sub]Mt (Meitnerium) (named after Lise Meitner, who collaborated with Otto Hahn to discover nuclear fission, and was overlooked when he won the Nobel Prize in 1945), and [sub]110[/sub]Ds (Darmstadtium). However, I was at the GSI from about 1988 to 1990, so that was after the isolation of Hs, and Mt, and before the isolation of Ds. Also, I was in a different workgroup than the one actually trying to synthesize these heavy elements.
In fact, the GSI has gotten as far as [sub]112[/sub]Uub (Ununbium). What is interesting is that an isotope with 114 protons and 184 neutrons (so that would be [sup]298[/sup]Uuq: Ununquadium) might have a half-life that can be measured in hours instead of milliseconds. Shell theory predicts an “island of stability” around this nucleide.
Titanium is valued for it’s strength-to-weight ratio. An equivalent weight of Titanium is stronger than steel.
The former Soviet Union, which had (has?) plentiful reserves of refinable titanium ore, made its jets fighters (e.g., the Foxbat) out of Titanium at a time the U.S. was using aluminum and steel alloys. It made for some light and fast airplanes!
However, this does not mean Titanium is stronger than steel, per volume, and I don’t have those figures on tensile strength to compare them (nor do I know the comparison to aluminum).
And another however, this does not take into consideration hardness (as measured on the Mohs scale). Titanium is softer than any steel alloy. Not sure if it is softer than iron.
Platinum (from the RL ‘plata,’ meaning silver) is a rare, soft, precious metal. The appearance of the two metals (whitish silver) is similar, but regarding weight, Platinum is heavy and titanium is light. Platinum is also much softer.
S¬
“I wanted to be a gym instructor, but they told me it was a three step process.
First I had to get abs of steel. Then they said that wasn’t enough. So I got abs of titanium. Then that wasn’t enough. Next step, abs of plutonium.
Now I like basketball as much as the next guy, but I’m thinking by the end of this, my abs are going to read like their own little periodic chart!” Michael Chamberlain 
Titanium is a much greyer metal than platinum, appearance wise.
Having recently been in the market for a plain wedding band, and having no interest in gold, I settled on either platinum or titanium. Equivalent, no-frills, half-dome bands cost about $300 in Pt and $90 in Ti. Titanium is very difficult to work with, most rings are not repairable beyond refinishing… simple designs can be resized larger, usually only a single size, by stretching. So, a larger portion of the Ti ring’s cost goes to manufacturing (or maybe not, most of the simpler rings are made by cutting off sections of titanium piping).
Just bulk metal, Pt is easily hundreds of times more expensive.
Even then they can occur in nature, Technetium has been noted in the spectra of some stars.
http://pearl1.lanl.gov/periodic/elements/43.html
I’ve always worked with it in a dissolved form.
The price of Titanium is given to be $100/lb from this site:
http://pearl1.lanl.gov/periodic/default.htm
Versus their price of $500/ounce for Pt back in 1990.
$100/lb sounds a bit expensive. That’s either out of date, or reflects a premium for very high purity in powdered form. As we noted above, “sponge” prices are in the range of 3 or 4 dollars per pound. “sponge” is the way raw titanium is sold as a commodity, and I suspect that the quotes of $3 to $4 / lb are for buying large quantities. This link gives some quotes from late 2003 for various forms (bottom of the page):
http://articles.findarticles.com/p/articles/mi_m3MKT/is_40-1_111/ai_108657042
$5/lb in ingot form, $8/lb in “commercially pure” plate. Again, I suspect you can only get that kind of price if you are buying tons of the stuff.
And it may get cheaper - a lot of the price reflects the difficulty of the current manufacturing process:
Strength is a property of the metal that is independent of weight or volume.
Commercially pure titanium has a strength of about 50 ksi, which is less than many common steels. However, like steel, the properties of titanium can be greatly altered by alloying.
Someone may debunk this as an urban myth, but I am under the impression that titanium rings can create a bit of an emergency if they have to be cut off for such things as injuries that cause swelling of the fingers. Tools that work for gold rings won’t make a dent in a titanium ring.