Many quartz crystals have visible areas of previous contact with other crystals. Because the other individual crystals in the family grew so close, and the crystals were not on a parallel growth path, the quartz formed in such a way as to compensate for the other's presence in the ordering of molecules.
  It may help to picture the way that a tree growing right next to a chain-link fence will, in time, envelope parts of the fence as it grows. In resting one’s finger or thumb on the contact impression of a quartz crystal one may note that the digit enters below the “surface barrier” of the crystal rather than merely resting on the flat face of the stone.
  This point of contact is an ideal way to enter and exchange with the vibrational frequency of the quartz crystal in a way with which it was formerly accustomed. The crystal actually compensated in molecular structuring and formed specifically in order to have an exterior member present in that area.

   At a glance, this apparent mineral inclusion appears to be calcite, judging by its silvery-whitish color and rhomboid form. Upon closer inspection, however, one may perceive that there is a small opening on the quartz surface, indicating that it is actually a hollow rhombohedral cavity with traces of a reddish clay-like material near the opening.  
This type of cavity is known as an "inclusion void" and the example shown in the photo is the natural cast of a calcite mineral that dissolved away during the formative phase of the crystal, leaving a perfect impression of itself inside the optically clear quartz.  Often an inclusion void may be entirely enclosed within the quartz host, making positive identification difficult.

   Whether an actual mineral inclusion exists within the cavity, or if it is merely an empty void in the form of the mineral that was formerly present, may be difficult to determine.  In this particular case the mineral cast is near to the surface of the quartz crystal and the opening to the hollow interior is visible, a clear indication of an inclusion void.                                                             "inclusion voids" -Inclusions in Quartz

  Himalayan quartz crystals form at breathtaking altitudes, often high above the peaks of all other mountains on Earth. Occurring in conditions very similar to those found in the Alpine regions of Europe, specimens of seldom seen clarity have recently been discovered.
  For centuries geologists and mineral enthusiasts in Switzerland, Austria, France and Italy, have collected some of the same rare quartz habits and formations which are now being found in the Himalayas of Nepal and Northern India.
  Many of these world famous formations and habits of quartz were individually named for the Alpine regions in which they were first discovered and documented, others were later identified by crystal healers and lightworkers. The term for the conditions in which some of these crystals form is “Alpine–type”. The word ‘type’ has been more recently added to the title of this geological rarity to account for it’s discovery in localities other than the Alps of Europe or Switzerland.
  Quartz crystals found in Alpine-type clefts, or fissures, are known for their extraordinary clarity, as they have formed in some cases over millions of years, creating prized examples of the highest purity possible in this, the most abundant mineral on Earth.
Not all Himalayan quartz is from Alpine-type clefts and not all Alpine-type clefts produce quartz crystals, further emphasizing the rarity of these special stones. Most Himalayan quartz comes from easier to reach localities at lower altitudes and is far less clean and clear than it’s higher altitude relative, often with a residual coating which proves difficult to remove.
  In some western localities the use of explosives to burrow into the hillside is quite a common practice and sadly, many crystals seem to be unearthed before their time and were, in our opinion, not ready to see the light of day.
  Venturing to high altitudes in search of these rare gifts of nature has been a lifelong passion and our gratitude is shown in our work. Using only simple hand tools, each of our Himalayan quartz crystal is ecologically collected from Alpine-type clefts or hydrothermal pockets which have been exposed by countless aeons of erosion and tectonic movement.