Biotite (pack/10) The Carolina Pledge: 100% Satisfaction Guaranteed. All of our products are unconditionally guaranteed. If for any reason you are not satisfied with any item, you may return it for a replacement, a refund, or credit. It's that simple. From our beginnings in 1927, Carolina Biological Supply Company has grown to become a leading supplier of science teaching materials for all levels of education. Today, from our headquarters in Burlington, North Carolina, we serve customers worldwide, including teachers, professors, homeschool educators, hobbyists, and professionals in health and science-related fields. When you shop with Carolina, you're not alone! All of our products are backed by unparalleled technical support, available from 8am to 8pm, ET, Monday-Friday. Contact information (Live Chat, email, and phone) is provided after placing your order at Amazon.