A skeptic responds with an explanation of how my 2 arahant relics became 4

A skeptic responds with an explanation 

of how my 2 arahant relics became 4.

(the following is a condensed version of his response)

Crystalline minerals naturally occur from cremation. You can in fact pre-order the color of these crystals by manipulating the temperature of the fire or other conditions in which cremation takes place. 

Buddhists are among the few groups of people who actively look for them, therefore they find them and assume that they somehow have a monopoly on the "miracle." 

Scientists have found a few unflattering facts about them: E.g. Virtually all the ones that are ascribed to ancient saints and are tested, are shown to be much more recent than the presumed history, and often from animals (e.g. dogs, parrots, and in one interesting case, donkey), rather than from humans. 

Crystalline minerals are known to naturally split off, "grow," change in color, etc. They in fact do so even in relatively inert environments.

I'm familiar with those Pure Land stories and other accounts from different traditions. Once again, sobering facts can be marshaled if those accounts are scrutinized. I personally know of a few "miracle" tales that are clearly fabricated, or given to contradictory testimonies by different people.

I am militantly against reductionist materialism. But I also know how sloppily people appeal to the supernatural, being deeply aware of the historical and psychological mechanisms with which these accounts are formed, perpetuated, and exaggerated.

 My first instinct is informed by the Buddha's attitude toward relics and assumed deva's involvement (in teleporting new guest relics)--that they are not spiritually significant.

When I studied psychology at school, we've done a fair share of experiments on confirmation bias--how we over-estimate the "hits" we have with our instincts, on how our instincts "checked out." I'm not asserting whether your own encounter is like this one or the other.

Here are videos on how to “grow” relics and other crystalline structure. As relics absorb moisture in air, they “multiply.” Here's one where they accelerated the process by pouring water onto them:

This one shows how the “growth” can be of a different color than the original:

The following is from "Scanning electron microscope observations of heat-treated human bone," by Holden JL, Phakey PP, Clement JG., Department of Physics, Monash University, Clayton, Victoria, Australia:

"This report describes the heat-induced alterations in human bone tissue observed using scanning electron microscopy and microradiography. Femoral bone samples were taken from persons varying in age from 1 year to 97 years at the time of their death. The bone was heated at selected temperatures in the range 200-1600 degrees C for periods of 2, 12, 18 and 24 h. Macroscopically, changes in colour occurred, together with some shrinkage, fracturing and distortion. However, dramatic changes occurred at the ultrastructural level. These changes included the progressive combustion of the organic portion of the bone tissue up to 400 degrees C and recrystallisation of the bone mineral beginning at 600 degrees C. Recrystallisation produced a range of crystal morphologies: spherical, hexagonal, platelets, rosettes and irregular. Crystal growth occurred at temperatures > 600 degrees C. Sintering led to fusion of crystals at 1000 degrees C. This process continued up to temperatures > 1400 degrees C. At 1600 degrees C the bone mineral melted. On heating, the morphology of crystals formed, and the ultrastructural changes which occurred, were found to be related to the age of the deceased, the temperature to which the bone had been heated and the duration of heating. These results are of importance to forensic scientists, arson investigators and paleoarcheologists in their investigation of cremated human bones, particularly when only fragments of bone are available, in order to determine something of the life history of the deceased and the circumstances surrounding the death."

...And just half-jokingly, no offense intended: next time, ask the deva to drop something other than a material of the same crystalline structure, so to obviate any doubt that the additional pieces were simply natural growth. I'd say a good chunk of gold nugget would be really good. If they can sneak a molecularly similar material into the container, why don't they sneak in something entirely different, as to best a skeptic's expected queries?