Reddit mentions of RSVP White Marble Mortar and Pestle

Get a mortar & pestle and gel caps. Grind super fine, and pack them super tight by tamping it down. I use 00 caps and 1 or 2 is enough to stay good for a few hours.

EDIT: You can use smaller caps, like '0' for a smaller dose. What I use, for the lazy:
00 Caps
0 Caps
Mortar & Pestle

I am not sure of what you already have or what you would need, I am listing a few things on top of my head:

• Crock pot
  
• Cast iron skillet
  
• Dutch oven
  
• Victorinox chef knife
  
• Microplane zester
  
• Bread maker machine
  
• Mandoline
  
• Mortar and pestle
  
• Flour Water Salt Yeast: The Fundamentals of Artisan Bread and Pizza
  
• Tartine bread
  
• Essentials of Classic Italian Cooking
  
• Espresso maker
  
• Cookie Sheet and cooling racks
  
• Meat Thermometer

I got married last summer and here are a few inexpensive items I would have loved to receive:

• [ Personalized Giving Tree Cutting Board ] (https://www.etsy.com/listing/203759519/on-sale-personalized-cutting-board?ref=br_feed_23&br_feed_tlp=gifts) $37; Etsy
  
• [ Succulent Frame ] (https://www.etsy.com/listing/206642420/succulents-in-a-8-x-8-frame-makes-a?ref=shop_home_active_1) $125; Etsy
  
• [ Personalized Wedding Date Frame ] (https://www.etsy.com/listing/96007470/personalized-wedding-gift-unframed?ref=br_feed_14&br_feed_tlp=gifts) $30; Etsy
  
• [ Bocce Ball Set ] (http://www.amazon.com/Trademark-Games-Piece-Bocce-Nylon/dp/B001ZEV5EA/ref=sr_1_1?ie=UTF8&qid=1426470191&sr=8-1&keywords=bocce+ball+set) $45; Amazon
  
• [ Avocado Slicer ] (http://www.amazon.com/OXO-Grips-Avocado-Slicer-Green/dp/B0088LR592/ref=sr_1_1?ie=UTF8&qid=1426470360&sr=8-1&keywords=avocado) & [ Mortar & Pestle ] (http://www.amazon.com/RSVP-White-Marble-Mortar-Pestle/dp/B000BUB58K/ref=sr_1_1?ie=UTF8&qid=1426470413&sr=8-1&keywords=mortar+and+pestle) $10 & $15; Amazon
  
  

Mortar & Pestle. They can usually be found at big-box stores or kitchen supply places...and Amazon of course.

http://smile.amazon.com/RSVP-White-Marble-Mortar-Pestle/dp/B000BUB58K

That just seems like a stupid tool. If you simply must use rocks to smash food, get better rocks, like marble or something.