Regarding Gratitude vs Appreciation...

Sometimes there are long-standing feelings of gratitude within people that trip them up, because when you feel grateful you are looking right at the problem that you overcome.

So when you feel gratitude because someone pulled you out of poverty, or you feel gratitude because someone liberated you in some way, that very gratitude is laced with the vibration of overcoming something unwanted and it is responsible for some sticking stuff in your vibration.

Gratitude leans resistance-ways, appreciation leans allowing-way.

In other words, they are two very different vibrations.

Abraham-Hicks, Alaska Cruise 2008, CD 5

Regarding your mental states question, I'm not sure this is possible to answer absolutely. This is because different words represent different emotions to different people.

Emotions that represent more personal empowerment to an individual (i.e. more freedom, control over your own life, personal power etc) will always feel better to an individual than emotions that feel less empowering.

But it's not always easy to distinguish the words that are attached to the emotions since they can be different for different people based upon their understanding of language and their usage and experience of it. For example, is a feeling of delight more or less empowering than a feeling of joy?

The Gratitude vs Appreciation one is easier to distinguish because, as Abraham say, the vibrations behind them are actually very different and most people will understand the difference when it is explained to them, even though the words are sometimes (mistakenly) used interchangeably.

In training as an NLP practitioner some years ago, I learned that sometimes it is better to not even force a client to identify a mental state. Just calling one state Blah and another Yuck is enough to create a thought-based link with which to change vibrational attitudes.

Sometimes the actual words just get in the way.

Gratitude to me is truly being in the moment, thankful for it. It is being thankful.

Appreciation is truly being in the moment and enjoying it. It is valuing what you have.

Example in Oliver Twist the boy had gratitude for what he was given, but appreciated it so much that he asked for more. We can be grateful for everything but how much do we appreciate it.

You are grateful to gift giver and you appreciate the gift. You can be grateful for the gift but you can't gratitude the gift you appreciate the gift. Appreciating the gift is being grateful for having it.

So I see gratitude as thankfulness and appreciation as the action of enjoying that which you are thankful for.