Invaluable (adjective)

1. Incalculably valuable or precious; too valuable to be measured or valued.
2. Having qualities or abilities that are so rare and useful that they cannot be measured or valued.

Origin:

Late 16th century: from french inestimable, from in- (expressing negation) + estimable (see estimable).

Examples:

1. The diamond was invaluable to the owner.
2. The support provided by her friends was invaluable to her during the difficult time.
3. His advice was invaluable to the company during the merger.
4. The experience she gained was invaluable for her future career.
5. The information provided was invaluable for the investigation.