FAQ

FREQUENTLY ASKED QUESTIONS

Q:  What exactly is lapidary?

A:   Generally speaking, lapidary is the shaping of stone, excluding sculpture.  Finished pieces can range from tiny enough for the most delicate of jewelry to large enough for a tabletop.

Q:  I have a rock that's about 5 1/2" around.  How big a saw do I need to cut slabs from it?

A:  A good rule of thumb is that you'll need a blade twice the size of your rock, plus at least an inch.  So figure on a 14" blade.  Bigger will also work.

Q:  What's the difference between a trim saw and a slab saw?

A:   A trim saw is smaller, usually a 6" blade, and a less powerful motor.  It's not meant to slab a piece of rough.  It's best used to trim off unwanted material from a slab to speed up the grinding process.  Slab saws have more powerful motors and sturdier blades and so they can handle larger rough material.

Q:  How do I know how big a tumbler I need?

A:  The size of the tumbler is directly related to the number of rocks you want to polish.  If you have a lifetime's worth of rocks to polish (and we have customers who fit that description!), you'll probably be happier with a larger machine, and one that is a little faster, such as the Covington and Thumbler models.  If you're a beginner, and want to just try it to see if you like it, go with our less expensive models.

Q:  Why do I need all that grit for my tumbler?

A:  Working stone is similar to working wood.  You start with a coarse grit, and work your way through to the finest to achieve a beautiful shine.  A carrier such as Old Miser can speed up the process.

Q:  What's the best way to drill a hole in my finished stone?

A:  You'll get better results using a hand-operated rather than an automatic drill press.  You'll have more control when it comes to keeping the stone wet, and keeping the bit vertical, as well as gauging the depth of the hole.  First rule:  keep your work under water!  Second rule:  when you're engaging the stone, you have to use a momentary up and down tap so that the stone and the bit both cool and the water flows into the hole.  Third rule:  it's probably going to take you a couple of bits to get the feel of the drilling motion so that you don't burn the bits up.  Fourth rule:  Be patient!  You'll probably get six quarter-inch deep holes per bit.  After you've refined your touch, you may be able to stretch that into eight to twelve on agate.  Fifth rule:  Do not use a Covington Automatic Gem Drill for stones over 6 on the Mohs scale. 

Q:  How do I know what size drill bit to order?

A:  It depends on the size of whatever you need to insert in the hole.  Best is no less than .25 mm over the size of your jumpring or cord.  Bigger is better here.

Q:  How can I learn more about the lapidary arts?

A:  Some community colleges teach lapidary arts.  Local rock clubs can put you in touch with teachers, too.  While we carry some quality books with excellent information, there's just no substitute for hands-on experience.

Q:  How can I get one of your catalogs?

A:  We don't publish a catalog.  That way, we can keep prices down, and save a tree or two.

Q:  Why the extra charges on my order through the Grobet catalog?

A:  Grobet may charge an extra $6 for orders under $80.00.