The idea of "Black Golden Heart Crystal" is dropping "Golden Heart Crystal" into growganoth instead of dropping golden items.

That's what you get from growganoth if you drop your Golden Heart Crystal:
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And you can make any "Black Golden" items with the same recipe you're using to make golden items.

Here's some examples:

Ɛ-o-3 Black Gold Angel Wings Ɛ-o-3
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Ɛ-o-3 Black Gold Teeny Angel Wings Ɛ-o-3
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Ɛ-o-3 Black Gold Diaper Ɛ-o-3
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Ɛ-o-3 Black Gold Neck Ɛ-o-3
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Ɛ-o-3 Black Gold Heartbow Ɛ-o-3
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Ɛ-o-3 Black Gold Heavenly Scythe Ɛ-o-3
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Ɛ-o-3 Black Gold Heartstaff Ɛ-o-3
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Ɛ-o-3 Black Gold Talaria Ɛ-o-3
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