irreplaceable

US /ˌɪr.əˈpleɪ.sə.bəl/
UK /ˌɪr.əˈpleɪ.sə.bəl/
1.

insubstituível

too special, unusual, or valuable to replace with something or someone else:

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Most of the porcelain you see in the display cabinets is irreplaceable.