In this quote from William LePar's spiritual source, The Council, they give some insight into the use of lapis. They also provide a warning to the questioner about this particular stone. At the end of their message they point out the general value of wearing those stones and metals that are beneficial to humankind.
The Council: The lapis is a stone that contains extremely high vibrations and overindulgence in such vibrations can be as detrimental to an entity as it can be helpful.
Some people can use lapis on the bare skin. Very, very few can do this. It should be, for the general understanding, should be worn away from the skin. In other words the stone should never be worn around the neck where it actually comes in contact with the skin itself. In this case, it should be encased in some sort of covering, one that is completely sealed off. The lapis in the case here, we would suggest wear it as you feel or desire to, but do not allow yourself to get into the habit of wearing the lapis. When you have a desire to wear it, wear it for a matter of a few hours and then remove it until you definitely feel the desire to wear it again.
Questioner: Yes, would you give me an idea how it would affect my life to wear lapis?
The Council: Lapis is not a stone that we would advise you to wear very often. It has a tendency to overexcite the emotional aspects that run closely with the spiritual and for you now at this time we would suggest that you wear it only on extremely rare occasions. If we were to put it this way, if tomorrow you have a desire to wear lapis, then do not wear it, but the next time do wear it.
Each stone or metal has many effects on the individuals, some are more effective on individuals than others, and it is not really wise to become too involved with such things. In certain cases it is very beneficial but as a general rule we will not make it a policy to go much into such things.
We have given you a number of stones to be carried on your person and a metal. The stones and the metal can do nothing for you, absolutely nothing in themselves. The only time they become effective for you is with the proper frame of mind. It is true that every element created has a vibration or an energy and as the elements are combined they have a combined effect of each of the elements. With the stones that we gave you, those will truly help you, but only if your attitude or your heart is in the right place; because as this energy or vibration is brought in contact with the body, it is magnified by the sincerity and the purity of the heart and the mind, and thus it helps to rebalance the spiritual and the material aspects of the body, but the amplifying source is the heart and the sincerity to truly develop spiritually. Without this then you might as well throw the stones away, you might as well throw the metal away, for you would only be carrying excess baggage.
For more on William LePar see www.WilliamLePar.com
For more on his spiritual source, The Council see http://www.williamlepar.com/faq#!faq/c1mwp