White quartz pebbles

My interest having been piqued by a mention of Bruce's blog, I tried to track down a digital copy of Wendy Berg's Red Tree, White Tree. Failing to find one, I instead downloaded the one Wendy Berg book I was able to find: Gwenevere and the Round Table. Scrolling through it rapidly first to get the lay of the land, I stumbled upon this, which seems to be from some sort of visualization exercise:

[Gwenevere] is standing where a stream of milk-water runs down the beach and into the sea. It flows over a bed of tiny white pebbles. She steps into the stream, and begins to walk upwards through its flowing water. She indicates that you should do likewise. You walk over to it. It is running fast over the white polished quartz pebbles, forming tiny whirlpools and eddies which splash into the air and catch the light. You kneel down and dip your hand into it, expecting it to be icy cold. But the water feels like dry, powdery snow flowing past your fingers. You look through the water to the stream-bed but it is hard to gauge the scale of what you are seeing. You can see your hand in the water, and the white pebbles, but they seem to lie a vast distance away, as if the stream bed lay within the stars.

The sound of the water fills your ears. It is like tiny silver bells, ringing faintly but rhythmically. There is an underlying rhythm, a pulsating, as if you are hearing the music of the stars.

Gwenevere continues to walk up the stream, moving effortlessly through the milk-white water. You step into the stream and follow her. You have eyes only for the white stream, and the sparkling quartz pebbles of the stream bed. You carefully watch your step to keep your balance, your eyes on the water swirling past your feet. It has a mesmerising effect. You feel as if you are leaving the earth behind you and walking out into the stars. 

I've just posted about white quartz, in "The Son of Righteousness, and the Talking Quartz of Kirtland," and about white pebbles in "The pebble key." I had not the slightest expectation of running into the same theme in a book about faeries and Arthurian legend, but there it is.