A Double Crescent Cross is frequently seen in jewellery where two crescents form a cross.
Somebody kindly sent us the photo (right) of necklace from India. As far as we now, there is no particular Indian connection to this symbol since the crescent moon is a relatively minor feature in the artwork of India's main religion, Hinduism.
Waxing and waning moons are common in Pagan wicca and the occult. (See Lunate Cross and Kaballah Cross)
In a Christian context, such a symbol could represent two nails that have bent from being extracted from the cross. (See Passion Cross)
The Evangelical Church of the Augsburg Confession in Austria (ECACA - Evangelische Kirche Augsburgischen Bekenntnisses) has a logo of a stylised cross in two separate parts. Yet as Lutherans, they believe in the Hypostatic union, the inseparable dual natures of Jesus Christ.