I found three envelopes which had Cartier on the labels. Between the three envelopes there are two crystals. Both of the crystals measure approximately 16.9 mm X 14.9 MM although one of the crystals was in the Grace Crystal Tank envelope.
I believe they both should be in the envelopes which have X1709 and C 170/9 Cartier 150 on the envelope since they both measure the same size.
Regardless, I took a number of close up photos to give you a good look. Both crystals are in very good condition.
Please see photos and email with questions.