Emulsion?

[Big Al]

Hi, worried newbie here...... got the car, a 1999 Rx7 just over a week ago. Since then I have done a fair bit of mileage in it and loved every minute. Thing is,  just inside the oil filler cap I am finding a light emulsion, similar to vaseline in consistancy, slightly opaque,
Not at all like the thick gunk I have seen on piston cars when the head gasket has failed.
Is this  an ominous sign or something they all do, please?

[chrisJDM]

i have heard in some cases this can be caused by some types of oil being used and is nothing to be worried about

[RobbieRX-7]

Normal. Nothing to worry about, and loads of people new to the car ask the same question

[chrisJDM]

dont you get it when you use mineral oil??

[Big Al]

Thanks Chris and Robbie for putting me out of my misery....phew !!!
Using GTX at the moment as this was the oil recommended by the guy who sold it to me.
Looking at this website I realise oil is a whole new subject though.