What is the mineral composition of each type of ore?

As per the Evelopedia, this is the composition of all ores in their base variation and at 100% efficiency. The numbers denote batch size and output respectively.

Arkonor - 200

• 10000 (~95.25%) Tritanium
• 333 (~3.17%) Megacyte
• 166 (~1.58%) Zydrine

Bistot - 200

• 170 (~1.36%) Megacyte
• 12000 (~95.92%) Pyerite
• 341 (~2.73%) Zydrine
   

Crokite - 250

• 331 (~0.85%) Nocxium
• 38000 (~97.45%) Tritanium
• 663 (~1.70%) Zydrine
   

Mercoxit - 250

• 530 (100%) Morphite
   

Spodumain - 250

• 71000 (~88.56%) Tritanium
• 140 (~0.17%) Megacyte
• 9000 (~11.23%) Pyerite
   

Plagioclase - 333

• 256 (25%) Mexallon
• 256 (25%) Tritanium
• 512 (50%) Pyerite
   

Pyroxeres - 333

• 120 (~11.61%) Mexallon
• 11 (~1.06%) Nocxium
• 844 (~81.62%) Tritanium
• 59 (~5.71%) Pyerite
   

Scordite - 333

• 833 (~66.69%) Tritanium
• 416 (~33.31%) Pyerite
   

Veldspar - 333

• 1000 (100%) Tritanium
   

Dark Ochre - 400

• 500 (~1.90%) Nocxium
• 25500 (~97.14%) Tritanium
• 250 (~0.95%) Zydrine
   

Gneiss - 400

• 700 (~8.50%) Isogen
• 3700 (~44.92%) Mexallon
• 3700 (~44.92%) Tritanium
• 137 (~1.66%) Zydrine
   

Kernite - 400

• 386 (~24.98%) Isogen
• 773 (~50.03%) Mexallon
• 386 (~24.98%) Tritanium
   

Hedbergite - 500

• 708 (~51.16%) Isogen
• 354 (~25.58%) Nocxium
• 290 (~20.95%) Pyerite
• 32 (~2.31%) Zydrine
   

Hemorphite - 500

• 212 (~12.97%) Isogen
• 60 (~3.67%) Mexallon
• 424 (~25.95%) Nocxium
• 650 (~39.78%) Tritanium
• 260 (~15.91%) Pyerite
• 28 (~1.71%) Zydrine
   

Jaspet - 500

• 518 (50%) Mexallon
• 259 (25%) Nocxium
• 259 (25%) Tritanium
   

Omber - 500

• 307 (~41.66%) Isogen
• 307 (~41.66%) Tritanium
• 123 (~16.69%) Pyerite

For further values (such as those for other ore variations), there is also a spreadsheet on the Evelopedia. Please note: This spreadsheet is currently outdated as per the Odyssey expansion.

All of the values below are assuming the following;

• Perfect mining yield (so no minerals are lost in the refining process)
• Enough standing with the corporation whose station you're using to refine (so they don't take any ore off you)

In addition to the below, each type of ore comes in three variants, one which yields +5% to the above figures (for example, Concentrated Veldspar, Pure Jaspet, Iridescent Gneiss, etc) and one which yields +10% to the above figures (for example Dense Veldspar, Pristine Jaspet, Prismatic Gneiss, etc). These are clearly marked on the information pages for the ore itself.

Legend

Batch        Batch size for refining
TRI          Tritanium
PYE          Pyrite
MEX          Mexallon
ISO          Isogen
NOC          Nocxium
ZYD          Zydrine
MEG          Megacyte
MOR          Morphite

Refining Outputs

             Batch   TRI    PYE   MEX   ISO   NOC   ZYD   MEG   MOR
Veldspar      333   1000    N/A   N/A   N/A   N/A   N/A   N/A   N/A
Scordite      333    833    416   N/A   N/A   N/A   N/A   N/A   N/A
Pyroxeres     333    844    59    120   N/A   11    N/A   N/A   N/A
Plagioclase   333    256    512   256   N/A   N/A   N/A   N/A   N/A
Omber         500    307    123   N/A   307   N/A   N/A   N/A   N/A
Kernite       400    386    N/A   773   386   N/A   N/A   N/A   N/A
Jaspet        500    259    259   518   N/A   259   8     N/A   N/A
Hemorphite    500    650    260   60    212   424   28    N/A   N/A
Hedbergite    500    N/A    N/A   N/A   708   354   32    N/A   N/A
Gneiss        400   3700    N/A  3700   700   N/A   137   N/A   N/A
Dark Ochre    400   25200   N/A   N/A   N/A   500   250   N/A   N/A
Crokite       250   38000   N/A   N/A   N/A   331   663   N/A   N/A
Spodumain     250   71000  9000   N/A   N/A   N/A   N/A   140   N/A
Bistot        200   12000   N/A   N/A   N/A   N/A   341   170   N/A
Arkanor       200   10000   N/A   N/A   N/A   N/A   166   333   N/A
Mercoxit      250    N/A    N/A   N/A   N/A   N/A   N/A   N/A   530