In a pouch around my neck I usually carry a large HEMATITE (stabilizes, grounds, protects). It was given to me by a friend. She had it lying on a rabbit fur in her room together with other stones and I instantly fell in love with it. I touched it and said, that feels nice. It's so heavy. She smiled and said: It has been waiting for you here. I don't like it and I don't touch it but I knew someone would fall in love with it, so take it.
I also have a dark GARNET (bodily strength, endurance, passion), a green MALACHITE that is broken in two parts (protector of children, transformation, activates chakras, clarifies emotions, releases negativity) a OLIVIN I collected myself at El Golfo beach of Lanzarote and a CLEAR QUARTZ (power amplifier, cleansing, strengthens will, improves vitality and well-being) which is the only really translucent stone I touch and carry. Very unlike my birthstones, I prefer dark, earthy, firey and non-translucent stones. I never carry amethyst or aquamarine except for some tiny pieces of jewellery.
Placebo or not, having amethyst around my neck gives me the creeps, carrying my stones makes me feel good.